Incorporating the PMU measurements information in transient stability simulation can increase computing speed and enhance accuracy in the timedomain simulation. Based on the conventional alternating iteration technique, this paper presents two simulation methods combined with the PMU measurements information, in which the number of differentialalgebraic equations is reduced and so is the computational scale. The proposed methods have been tested and compared with the conventional method using the New England 10machine 39bus system and IEEE 50machine 145bus system. The cases with errors of the dynamic model parameter and PMU have been also simulated and discussed. The simulation results demonstrate the effectiveness of the presented methods.