Abstract: Reservoir simulation technology has been widely used for a long time in China. Compared with onshore oilfield, offshore oilfield development has its own special characteristics such as capital intensive, high risk, and limited drilling information. So its development strategy is different with conventional onshore oilfield development. Reservoir simulation technology can be used to study overall development scheme, development scheme adjustment, dynamic follow-up, and remaining oil distribution, and it also can be used to calculate and estimate reserves and set up 3D models. Application and effects of reservoir simulation technology in China was introduced and commented in this paper.