Abstract: Molecular dynamics simulations were performed to investigate the sliding of a Si probe on the graphene with vacancy or Stone-Wales (SW) defects and effects of various defects on friction properties of graphene. Simulation results show that friction on graphene with both kinds of defects were obviously larger than perfect graphene in the defect regions, which was attributed to the increasing energy dissipation resulted from the extended interface barrier potential of graphene due to vacancy. For graphene with SW defects, friction increased because the probe was hindered by the wrinkle which was formed by the dislocation of carbon atoms along Z direction owing to the SW defects. It is also found that friction of graphene with vacancy along X and Y axis both increased with the increasing defect concentration. The cause of the former result was that tangential interaction range between probe and vacancy along X axis was extended. And the reason of the latter result was that the interface barrier potential between probe and vacancy along Y axis was enlarged as defect concentration increased. In addition, the friction of graphene with vacancy along Y axis was larger than that along X axis, because the interface barrier potential between probe and vacancy along Y axis was larger than the other one while the tangential interaction range difference between probe and two kinds of vacancy defects was negligible. For graphene with SW defects, the friction of type 2 was larger than that of type 1 and the friction of type 2 along X axis was larger than that along Y axis. Reason was that adjacent pentagon carbon rings existed in the former two cases. It is easier for wrinkle formed for graphene with adjacent pentagon carbon rings in the former two cases, which resulted in larger friction through hindering the slide of probe by higher wrinkle. The results of the study improved the friction mechanism of the defects graphene, and provided the theoretical basis and guidance for the design and development of graphene micro-nano devices.