The invention discloses an instant messaging system for realizing interaction, which is used for the two messaging parties to realize interaction of the tracking information of any party through respective three-dimensional devices. The tracking information refers to the information of the user in the specified ranges around the three-dimensional devices. The instant messaging system comprises a first three-dimensional device and a second three-dimensional device. The first three-dimensional device is connected with first instant messaging software of the user of any party and is used for acquiring the signal that the user exists and sending the signal to the first instant messaging software. The second three-dimensional device is connected with second instant messaging software of the user of the other party. The second instant messaging software is used for sending the received signal to the second three-dimensional device and the second three-dimensional device is used for conveying the information that the user exists to the user of the other party. The instant messaging system improves the efficiency of conveying the information; meanwhile, the interest of using the instant messaging software is increased by using the three-dimensional devices.