We have developed a equipment for directly rolling widely used spring steel（60Si2Mn） in semi solid sate in order to examine the rheological behavior and regulation and to grope directly rolling forming technology available for semi solid steel. The results showed that plastic deformation behavior of the solid phases differed from that of liquid phase during rolling

resulting in the difference of microstructure and properties between the center and the outer side of rolled product. Most of solid phase concentrates in the center while liquid phase flows toward the outer side. Plastic deformation rate of solid phase particulate increases with the increase of the solid fraction. Micro crack in surface of the rolled product attributes to either lower liquid phase fraction or higher deformation rate in the semi solid slurry or larger thermal differential between surface of the roller and the rolled product.