Abstract: Using core flow equipment to run the test of water shutoff capability, three kinds of high temperature resistance gel systems with different intensity were studied. Some influential factors such as permeability, injection rate, water and oil phases were investigated. The results show that the gels present higher plugging capacity to water than that to oil.We suggest that this plugging selectivity is due to the different interactions between water gel and oil/gel while they pass through the core. When water passes through the gel treated core, it has no interactions with gel. Therefore, it appeared the behavior of Newtonian fluid.