th , 2012; revised: Sep. 24 th , 2012; accepted: Oct. 1 st , 2012 Abstract: Through the core flow experiment, the core displacement model was applied to monitor the pressure changes in the process of experiments to evaluate the block pressure difference and water plugging rate after the water shutoff system gel in cores, thus, it can provide a reference for field application. Found by experiment: the higher furfuryl al- cohol content, the greater the block pressure difference; the higher the gelling temperature, the smaller the block pres- sure difference; the greater the aqueous phase permeability before the block of stratum, the smaller the block pressure difference after consolidation. When other conditions remain the same level, the block pressure difference and the length of the core tube is basically a linear relationship. The water shutoff system optimized in the lower concentration still has good sealing strength when exposed to high temperatures. As to the core of different permeability, it still has a good blocking ability and its blocking rate is 99.0% or higher.