In this paper,a numerical simulation of the present 3-D tectonic stress field of the Zhangqiang Depression is made using Super SAP finite element program,the technology and methodology here developed can be applied to other petroliferous basins.A knowledge of the existing stress state of an oil basin may prove useful to a quantitative study of the history of the expulsion and accumulation of hydrocarbons,avoidance of damage to wellcasings,and to reasonable recovering of oil as well.