Abstract: In order to establish a method Real-time PCR for gene expression quantity study of Lactuca sative L.,with leaves of Lactuca sativa L. (S24) as material, we used SYBR GreenⅠmethod, compared two pairs of primers 18SR1/18SR2 in 10μL and 20μL reaction system related index though the amplification of Real-time PCR，the standard curve of Real-time PCR and the melt curve of Real-time PCR.Choose the optimal Real-time PCR system and house keeping gene primers in Lactuca sativa L.