Stopper device of drawer slide rail, including an outer slide rail, a middle slide rail, an inner slide rail, an outer stop section and an inner stop section. The outer slide rail is disposed on a cabinet body. The outer stop section is disposed at one end of the middle slide rail. The inner stop section is disposed in the inner slide rail. The inner slide rail is disposed on a drawer. The slide rails are slidably assembled with each other. The inner stop section is stopped by or disengaged from the outer stop section so as to easily connect the drawer with the cabinet body or separate the drawer therefrom.