Hi, You can try this approach: UniPropertyGrid1.AddProperty(['Prop1', True]); UniPropertyGrid1.AddProperty(['Prop2', 'B']); //combobox TExPGrid(UniPropertyGrid1).PopulateGrid; UniPropertyGrid1.JSInterface.JSCode(#1'.sourceConfig = {Prop2: {editor: new Ext.grid.CellEditor({field: new Ext.form.field.ComboBox({editable: false, store:["A", "B", "C"]})})}};');