Abstract: Abstract: Five main factors which affected SSR-PCR reaction: TaqDNA polymerase, Mg2+, primer, template DNA and dNTPs were studied with the Hevea brasiliensis plant material Zhenxuan 2 to screen the optimal reaction system. It was indicated by the results that the optimal reaction system of SSR-PCR for Hevea brasiliensis was 20 ul of total reaction volume containing 0.8 units of TaqDNA polymerase, 1.5mmol•L-1 of Mg2+, 0.5μmol•L-1 of primer, 0.25 mmol•L-1 of dNTPs and 50 ng template DNA. Fourteen plant materials, one primer pair and 8% polyacrylamidegel were selected to detect the reaction system. The results seemed that the optimal system was stable and credible which can build the basis on further study, e.g. genetic diversity assessment and construction of fingerprint etc. Key words: Hevea brasiliensis, simple sequence repeat (SSR),optimization