A passivity-based composite adaptive position control scheme for an induction motor is proposed in this paper. First, the dynamics of the induction motor is proved to be state strictly passive, and a composite adaptation algorithm is proposed to control the position of the induction motor. Then, the global stability of the induction motor position control system is formally proved by the passivity theory. Experimental results are provided to show that the good position tracking can be obtained without any information of the rotor flux. The proposed approach is robust to the variations of motor mechanical parameters and external load disturbances.