Abstract: Micro-gel flooding is a new technique combine properties of profile modification and polymer flooding, solved current problems such as polymer volume needed larger, temperature and salt resisting ability poor and compounding of polymer with wastewater is difficult. Flooding experiments are carried out at first time using micro- real-sand model in combination with the reservoir feature and development status in Xia’ermen Oilfield, the experiment results show that micro-gel flow into large porous firstly, then into little porous and throat by deformation, and diversion and viscous-elastic behavior are main micro-mechanism that micro-gel improve oil recovery.