Abstract: A magnetic polymer microsphere with stable structure and nano/micro sizes is introduced in this paper as deep profile control agent and water shutoff agent. Characterization analysis by scanning electron microscope, fourier transform infrared spectrometer and vibrating sample magnetometer prove the composite structure of inorganic magnetic silica oxide core and PAMAA organic shell in microsphere. Experimental results show that the magnetic composite polymer microsphere has good swelling capacity, plugging property, high temperature and salt resistant. The polymer microspheres are super paramagnetic, which not only benefits to magnetic separation from produced fluid but also can be used as magnetic water shutoff in oil wells. The composited polymer microsphere has a potential application as flooding profile control and water shutoff material for enhancing oil recovery.