diff --git a/controller/KissCount.cpp b/controller/KissCount.cpp
index d4e6f7a..2466319 100644
--- a/controller/KissCount.cpp
+++ b/controller/KissCount.cpp
@@ -116,3 +116,30 @@ void KissCount::DeleteAccount(struct Account ac)
     if (it->id == ac.id)
       _user->_accounts.erase(_user->_accounts.begin()+i);
 }
+
+void KissCount::AddCategory(wxString name, wxColour colour)
+{
+  wxString color;
+  color = _("#") ;
+  color += wxString::Format(_("%02X"), colour.Red());
+  color += wxString::Format(_("%02X"), colour.Green());
+  color += wxString::Format(_("%02X"), colour.Blue());
+
+  _db->AddCategory(_user, name, color);
+}
+
+void KissCount::UpdateCategory(wxString oldName, wxString name, wxColour colour)
+{
+  wxString color;
+  color = _("#") ;
+  color += wxString::Format(_("%02X"), colour.Red());
+  color += wxString::Format(_("%02X"), colour.Green());
+  color += wxString::Format(_("%02X"), colour.Blue());
+
+  _db->UpdateCategory(_user, oldName, name, color);
+}
+
+void KissCount::DeleteCategory(wxString name)
+{
+  _db->DeleteCategory(_user, name);
+}
diff --git a/controller/KissCount.h b/controller/KissCount.h
index 29769ee..d2f5f15 100644
--- a/controller/KissCount.h
+++ b/controller/KissCount.h
@@ -18,17 +18,24 @@ class KissCount
   std::list<wxString> GetUsers();
   bool IsValidUser(wxString user, wxString password);
   void LoadUser(wxString user);
-  void LoadYear(int year, bool force=false);
   User* GetUser();
-  double GetAccountAmount(wxString id, int month, int year);
-  void UpdateOperation(struct operation op);
+
+  void LoadYear(int year, bool force=false);
+
   wxString AddOperation(struct operation op);
+  void UpdateOperation(struct operation op);
   void DeleteOperation(struct operation op);
+
+  double GetAccountAmount(wxString id, int month, int year);
   void SetAccountAmount(int month, int year, wxString accountId, double value);
   void AddAccount(struct Account ac);
   void UpdateAccount(struct Account ac);
   void DeleteAccount(struct Account ac);
 
+  void AddCategory(wxString name, wxColour colour);
+  void UpdateCategory(wxString oldName, wxString name, wxColour colour);
+  void DeleteCategory(wxString name);
+
  private:
   wxUI* _wxUI;
   Database* _db;
diff --git a/model/Database.cpp b/model/Database.cpp
index 015b052..284f8c7 100644
--- a/model/Database.cpp
+++ b/model/Database.cpp
@@ -436,3 +436,80 @@ void Database::DeleteAccount(struct Account ac)
 
     EXECUTE_SQL_UPDATE(req, );
 }
+
+void Database::AddCategory(User* user, wxString name, wxString color)
+{
+  wxString req;
+
+  req = _("INSERT INTO preference ('user', 'type', 'name', 'value') VALUES ('") ;
+  req += user->_id + _("'");
+  req += _(", 'category'");
+  req += _(", 'name'");
+  req += _(", '") + name + _("'");
+  req += _(")");
+	    
+  EXECUTE_SQL_UPDATE(req, );
+
+  req = _("INSERT INTO preference ('user', 'type', 'name', 'value') VALUES ('") ;
+  req += user->_id + _("'");
+  req += _(", 'category_color'");
+  req += _(", '") + name + _("'");
+  req += _(", '") + color + _("'");
+  req += _(")");
+	    
+  EXECUTE_SQL_UPDATE(req, );
+}
+
+void Database::UpdateCategory(User* user, wxString oldName, wxString name, wxString color)
+{
+    wxString req;
+
+    if (oldName != name)
+      {
+	req = _("UPDATE preference SET ") ;
+	req += _("value='") + name + _("'");
+	req += _(" WHERE user='") + user->_id + _("'");
+	req += _(" AND type='category'");
+	req += _(" AND name='name'");
+	req += _(" AND value='") + oldName + _("'");
+
+	EXECUTE_SQL_UPDATE(req, );
+      }
+
+    req = _("UPDATE preference SET ") ;
+    req += _("value='") + color + _("'");
+    req += _(" WHERE user='") + user->_id + _("'");
+    req += _(" AND type='category_color'");
+    req += _(" AND name='") + oldName + _("'");
+
+    EXECUTE_SQL_UPDATE(req, );
+
+    if (oldName != name)
+      {
+	req = _("UPDATE preference SET ") ;
+	req += _("name='") + name + _("'");
+	req += _(" WHERE user='") + user->_id + _("'");
+	req += _(" AND type='category_color'");
+	req += _(" AND name='") + oldName + _("'");
+	req += _(" AND value='") + color + _("'");
+
+	EXECUTE_SQL_UPDATE(req, );
+      }
+}
+
+void Database::DeleteCategory(User* user, wxString name)
+{
+    wxString req;
+    req = _("DELETE FROM preference WHERE user='") + user->_id + _("'");
+    req += _(" AND type='category'");
+    req += _(" AND name='name'");
+    req += _(" AND value='") + name + _("'");
+
+    EXECUTE_SQL_UPDATE(req, );
+
+    req = _("DELETE FROM preference WHERE user='") + user->_id + _("'");
+    req += _(" AND type='category_color'");
+    req += _(" AND name='") + name + _("'");
+
+    EXECUTE_SQL_UPDATE(req, );
+}
diff --git a/model/Database.h b/model/Database.h
index 35bc076..b630c01 100644
--- a/model/Database.h
+++ b/model/Database.h
@@ -34,6 +34,10 @@ class Database
   void UpdateAccount(struct Account ac);
   void DeleteAccount(struct Account ac);
 
+  void AddCategory(User* user, wxString name, wxString color);
+  void UpdateCategory(User* user, wxString oldName, wxString name, wxString color);
+  void DeleteCategory(User* user, wxString name);
+
  private:
     wxSQLite3Database _db;
     
diff --git a/view/PreferencesPanel.cpp b/view/PreferencesPanel.cpp
index d8376e4..eef4435 100644
--- a/view/PreferencesPanel.cpp
+++ b/view/PreferencesPanel.cpp
@@ -158,11 +158,17 @@ void PreferencesPanel::InitCategories(User* user)
 	_categoriesGrid->SetCellAlignment(curLine, CATEGORY_COLOR, wxALIGN_CENTRE, wxALIGN_CENTRE);
 	_categoriesGrid->SetCellAlignment(curLine, CATEGORY_FONT, wxALIGN_CENTRE, wxALIGN_CENTRE);
 	_categoriesGrid->SetCellAlignment(curLine, CATEGORY_DELETE, wxALIGN_CENTRE, wxALIGN_CENTRE);
+
+	_categoriesIndexes[curLine] = it->second;
     }
 
     _categoriesGrid->SetReadOnly(0, CATEGORY_DELETE, true);
     _categoriesGrid->AutoSizeColumns(true);    
+
     _categoriesGrid->AppendRows();
+    _categoriesGrid->SetReadOnly(curLine, CATEGORY_COLOR, true);
+    _categoriesGrid->SetReadOnly(curLine, CATEGORY_FONT, true);
+    _categoriesGrid->SetReadOnly(curLine, CATEGORY_DELETE, true);
     SET_ROW_COLOR(curLine, OWN_GREEN);
 }
 
@@ -316,4 +322,75 @@ void PreferencesPanel::OnAccountModified(wxGridEvent& event)
 
 void PreferencesPanel::OnCategoryModified(wxGridEvent& event)
 {
+  int op_complete = 1;
+  wxString value, categoryName ;
+  User* user = _kiss->GetUser();
+  int row = event.GetRow();
+  int col = event.GetCol();
+  static bool inModification = false ;
+
+  if (inModification) return;
+
+  inModification = true;
+
+  value = _categoriesGrid->GetCellValue(row, CATEGORY_NAME);
+  if (value != _(""))
+  {
+      categoryName = value;
+      op_complete--;
+  }
+
+  // Categories modification
+  if (user->GetCategoriesNumber() && row < user->GetCategoriesNumber())
+    {
+      if (col == CATEGORY_DELETE)
+	{
+	  wxMessageDialog dialog(_wxUI, _("Are you sure want to delete : \n")+categoryName, _("KissCount"), wxYES_NO);
+	  if (dialog.ShowModal() == wxID_NO)
+	    {
+	      _categoriesGrid->SetCellValue(row, col, _("0"));
+	    }
+	  else
+	    {
+	      _categoriesIndexes.erase(row);
+	      _categoriesGrid->DeleteRows(row, 1);
+	      _kiss->DeleteCategory(categoryName);
+	    }
+
+	  _wxUI->Layout();
+	  inModification = false;
+	  return;
+	}
+      _kiss->UpdateCategory(_categoriesIndexes[row], categoryName, _categoriesGrid->GetCellBackgroundColour(row, col));
+    }
+  // New category
+  else
+    {
+      if (op_complete) 
+	{
+	  inModification = false;
+	  return ;
+	}
+      
+      _categoriesIndexes[row] = categoryName;
+      _kiss->AddCategory(categoryName, _categoriesGrid->GetCellBackgroundColour(row, col));
+      _categoriesGrid->SetReadOnly(row, CATEGORY_COLOR, false);
+      _categoriesGrid->SetReadOnly(row, CATEGORY_FONT, false);
+      _categoriesGrid->SetReadOnly(row, CATEGORY_DELETE, false);
+      _categoriesGrid->SetCellRenderer(row, CATEGORY_DELETE, new wxGridCellBoolRenderer ());
+      _categoriesGrid->SetCellEditor(row, CATEGORY_DELETE, new wxGridCellBoolEditor ());
+
+      _categoriesGrid->SetCellAlignment(row, CATEGORY_COLOR, wxALIGN_CENTRE, wxALIGN_CENTRE);
+      _categoriesGrid->SetCellAlignment(row, CATEGORY_FONT, wxALIGN_CENTRE, wxALIGN_CENTRE);
+      _categoriesGrid->SetCellAlignment(row, CATEGORY_DELETE, wxALIGN_CENTRE, wxALIGN_CENTRE);
+
+      row++;
+      _categoriesGrid->AppendRows();
+      _categoriesGrid->SetReadOnly(row, CATEGORY_COLOR, true);
+      _categoriesGrid->SetReadOnly(row, CATEGORY_FONT, true);
+      _categoriesGrid->SetReadOnly(row, CATEGORY_DELETE, true);
+      SET_ROW_COLOR(row, OWN_GREEN);
+    }
+
+  return;
 }