Abstract: The isotope tracer were injected into midlow permeability reservoir of Qinghai oil field using inter well tracer monitoring technique to evaluate the connectivity of between wells, explain the parameter of highpermeability channels, provide information for exploitation of oil filed. This technique adopt the method of qualitative and quantitative analysis, combining static datum and dynamic datum of reservoir to analyze connectivity of between injection wells and production wells, as well as the parameter of highpermeability channels. In fact, the application show it is very efficiency that the technique analyze connectivity between wells, identify highpermeability channels, and explain the parameter of highpermeability in midlow permeability reservoir.