Abstract: The influence of the status of billet steel, rolling compression ratio, deformation rate per pass on grain of 316 austenitic stainless steel medium plate was done in laboratory. The results explained that the total compression ratio is more than 6, the original structure of steel billet has no influence on grain size of hot rolling plate, when the total compression ratio is more than 6, the homogeneous grain in the whole thickness is obtained in condition of same billet steel heating- up temperature and deformation rate per pass. But when the total compression ratio is more than 6, the 2 grade and 7 grade duplex grain are obtained even though the deformation rate per pass is more than 30% , and when the total compression ratio is less than 10% , the grain is heterogeneous even though the total compression ratio is big enough.