In order to explore the effect of the injection rate and permeability on recovery by steam flooding after polymer flooding in thin oil reservoirs，after the water flooding and polymer flooding under 45℃,using the natural cylindrical cores and simulated oil of Daqing Saertu oil field,the experimental study of steam flooding of 3 groups of permeability and 4 steam injection rates of total 24 cores in the two temperature field conditions was conducted.The results showed that:at the same temperature of steam injection, when steam injection rate was low, the steam drive oil recovery would increase constantly as steam injection rate raised.And when steam injection rate was high, the fingering phenomenon intensifyed which caused the steam drive recovery tend to be mild, so there would be no practical value if the steam injection rate was too high and therefore the appropriate rate was 0.2ml/min in this experiment;the increase of permeability contributed to the increase of steam flooding oil recovery after polymer flooding,but it would intensify the rush of steam when permeability outranged 1 μm2,which had no benefits to EOR.With regard to medium permeability cores, raising the temperature of steam injection can significantly improve the steam drive oil recovery, but,for high permeability cores, it had little effect.