Abstract: In accordance with the problems on the production of continuous casting of low alloy steel at PZH Steel and based on the research upon effect of RE oxide(RE_xO_y) on the properties of mold powder and the reaction of RE elements to melting slag,mold powder with strong ability of absorption and solution of RE_xO_y and non-reaction to RE elements was developed through the choice of raw materials and the effect of fluxes on the properties of mold powder.From industrial scale experiment it is concluded that the developed mold powder has met with good results,such as the rate without slab surface finishing>90%,excellent lubrication and lower breakout rate.