Abstract:　The quenching at different temperature and the temper at high temperature affect the magnetic performance of stainless steel .It analyses microscopic structure、feature of carbide precipitation and content of retained austenite and explains how the magnetic performance changes. The result shows that as the austenitizing temperature is higher and ferrite content is more, the magnetic performance is better. The temper at high temperature can improve the magnetic performance greatly. On the other hand, if the temperature of austenitizing is too high, retained austenite is too much and crystal grain too big, the Magnetic Performance will be fall down.