A system and method of sharing an object based on a knocking input are provided. The method includes detecting a knocking input on sharing device, determining at least one object displayed on a screen of the sharing device based on the knocking input, and determining at least one counterpart device to share at least one object with, and sharing the at least one object with the at least one counterpart device, wherein the at least one object displayed on the screen of the sharing device is also displayed on a screen of the at least one counterpart device after being synchronized.