We made an on-site investigation about pedestrian violation of traffic signals at a signalized intersection in Xi’an,Shaanxi province,China.Based on it,we studied the impact of pedestrian’s waiting time on violation decision and the impact of the number of pedestrians in colony on the probability of swarming pedestrians’ violation.The result revealed that the probability of pedestrian violation rose with the waiting time for the pedestrians’ green signal.Then we developed a Monte Carlo model for simulating mixed vehicles and pedestrians and used the on-site investigation data to validate the model.When traffic volume is light,the error between the simulated values and the measured ones is 2.47%.When traffic volume is heavy,the error is 3.38%. We made an on-site investigation about pedestrian violation of traffic signals at a signalized intersection in Xi’an, Shaanxi province, China.Based on it, we studied the impact of pedestrian’s waiting time on violation decision and the impact of the number of pedestrians in colony on the probability of swarming pedestrians ’violation. the result revealed that the probability of pedestrian violation rose with the waiting time for the pedestrians’ green signal. If we developed a Monte Carlo model for simulating mixed vehicles and pedestrians and used the on- The investigation traffic to validate the model. The traffic volume is light, the error between the simulated values ​​and the measured ones is 2.47% .When the traffic volume is heavy, the error is 3.38%.