Abstract: Micro-gel is a micron-grade particle solution or dispersion gel solution ,mainly used in deep oil reservoir profile control,having the dual function of water control and oil displacement.It mainly relies on the micron particles swelling to block the pore throat,in addition,when the number of particles is accumulated in the throat,the resulted block can make water flow around completely and thus achieve its deep profiling effect step by step.Through extensive literature research,the paper focused on an overview of research on the micro-gel deep profile control system abroad,summed up the macroshape and the internal cross bonding structure of micro-gel,summarized the expansion properties under heating conditions and the mechanism of plugging of micro-gel,analyzed the impact of salinity and temperature on its expansion property.Its immigration in porous media and adaptation to oil reservoir have been studied,and the result shows the micro-gel is effective and promising in profile control.