Please refer this link How to add an empty item to ExtJS combobox?
Update: jsfiddle with that solution implemented: http://jsfiddle.net/q5e3J/3/
var combo = Ext.create('Ext.form.field.ComboBox', {
renderTo: Ext.getBody(),
displayField: 'name',
valueField: 'abbr',
value: 'AL',
store: Ext.create('Ext.data.Store', {
model: 'State',
data: states
}),
queryMode: 'local',
editable: false,
emptyText: 'No Selection',
listConfig: {
tpl: '<div class="my-boundlist-item-menu">No Selection</div>'
+ '<tpl for=".">'
+ '<div class="x-boundlist-item">{name}</div></tpl>',
listeners: {
el: {
delegate: '.my-boundlist-item-menu',
click: function() {
combo.clearValue();
}
}
}
}
});