Abstract: The grain inter-well tracer testing technology was a-dopted to make a study on the connecting circumstances in the process of Wangyao oilfield development,on reservoir heterogeneity characteristics,high permeable strip and de-velopment rule of large pores. The study results show that the technology is intuitive and quantitative,and can resolve the problems of semi-quantitative and multi-solution which exist in inter-well monitoring technology such as chemical tracer technology and radioactive tracer technology.