After several years of exploitation of Jurassic reservoirs in HJ oilfield，the development stage of some well areas came to middle and high water content stages. In order to ensure the stable production and enhance the oil recovery，the effect of polymer microspheres type and concentration and injection on the plugging rate was probed by the laboratory sand pack experiment，and the polymer microspheres deep flooding test was carried out in Jurassic reservoirs of HJ oilfield. The experimental results indicated that the permeability of sand pack with the similar core property to Jurassic reservoirs in HJ oilfield decreased by more than 85% when injected with 0.5 PV polyacrylamide nanoscale polymer microspheres solution with 5000 mg/L WQ100，whose initial particle size was 0.1 μm and swelling times was 5—20. The polymer microspheres deep profile field practice results in Yan 7 L242 well area and Yan 9 L141 well area showed that the WQ100 polyacrylamide polymer microspheres had good effect in the well groups whose reservoirs permeability was in 6×10^-3—9×10^-3 μm². When the reservoir permeability was above 9×10^-3 μm²，the effective plugging was not happened. In addition，polymer microspheres deep flooding didn't adapt to well groups which had poor physical property and high pressure water well.