Abstract: In view of the problems of high water sensitivity and vulnerability to pollution of some pools in mid-low permeability sandstone reservoirs in Wenmingzhai and Weicheng Oilfields, SJ-2 temporary well plugging agent is introduced and indoor experimental evaluation is made from five perspectives as follows: pumping, swelling, temporary plugging, dissolving, and permeability recovery. Indoor experiments show that the SJ-2 temporary well plugging agent features in good mobility when the concentration is lower than 2%. The maximum pressure to bear on the aqueous sandstone is 7 MPa, and the 72 h dissolution rate at the temperature of 85 ℃ tops 60%. The agent has been applied to 40 wells, 95% efficient. The agent can also be used to the mid-low permeability reservoirs, shortening the drainage period substantially and improving the production rate of oil wells effectively.