There are provided a method and system for authenticating a stamp touch. The method of authenticating a stamp touch according to the invention is executed in a wireless terminal having a capacitive touch screen which supports a multi-touch, the method including, a first operation in which N touch points touching a touch stamp having N (N≧5) touch units made of a conductive material on the capacitive touch screen are recognized, a second operation in which a touch authentication condition set for authenticating a touch using the touch stamp is used to check an authentication result of a geometrical position relation of the N touch points, and a third operation in which a designated service linked with the touch stamp starts when the N touch points are authenticated.