Finite element models about bus rollover and passenger restraint system were created according to ECE R66 requirements. Simulation and experimental study on the rollover test for bus and the dynamic test for bus seats were performed. The good agreement between the simulation results and the experimental data proves the accuracy of the finite element models used in the rollover simulation study. 4 Hybrid III 50% dummies were placed at the structurally weakest body section of the bus. And the injury risk of dummies with three different passenger restraint systems (no seatbelt,two-point seatbelt and three-point seatbelt) was respectively evaluated during bus rollover. Simulation results illustrate that the dummies with no seatbelt protection suffer great risk of head and neck injury. Two and three point safety belts provide somewhat similar protection of neck and chest for all the dummies. Most of the dummy heads are well protected by two-point seatbelts except the one that is placed in the outboard seating position on the struck side of the bus.