Abstract: In order to simulate steamflood in oil reservoirs a set of similiarity groups has been inferres with equation analysis method and engineering judgement. On such a basis, a vacuum physical simulated test equipment has been built. Taking two blocks, East-2 in Block 6 and Block 9 in Kelamay oil field, as prototypes, scaled models were made. A series of simulated test was carried out. The commen characteristics of two reservoirs are: the crude oil is a medium-viscous oil(viscosity 430～3300 mPa.s), the dinsity of the crude oil is rather light(0.91-0.92g/cm³)and the net thickness of both reservoirs are thin(about 13m). Main objects are studied on:(1)the effect of steam injection rate on oil recovery and oil-steam ratio,(2)the effect of injected steam quality on oil recovery and oil-steam ratio,(3)the effect of location of the perforetion,(4)the effect of initial oil saturation. The results of study on the effect of the paramiters and the analysis of the experimental phenomena are presented in this paper.