Abstarct: This thesis studies the problem of position tracking of bilateral teleoperation systems. This research is set in two parts. First, a kind of these systems with constant time delay in communication channel is investigated. For this system, a control structure is proposed such that in addition to guarantee the stability of the closed-loop system and position tracking in the presence of model uncertainties, the optimal parameters of the controller are obtained to achieve optimal position tracking using a novel optimization algorithm. In the second part, another kind of bilateral teleoperation systems is considered where the time delay in communication channel is included the time varying term. In this part, a structure is firstly introduced in which due to existence of this term the stability condition is not satisfied and thus the system is unstable. To solve this problem, using the wavelet transform and its preference in noise rejection, the time varying term is considered as a noise in the time delay in communication channel, the stability condition of the system is provided. Afterward, using iterative learning control, a structure is considered in addition to ensure the stability of the system and zero tracking error by increasing iterations, by using the control signal of stabilized system via wavelet transform as its initial control signal, the position tracking are provided better than before.