Abstract:In order to establish the optimal reaction of RAPD-PCR amplification for Eomecon chionantha Hance, the following parameters were optimized: the concentrations of Mg2+, template DNA, dNTPs, primers and Taq DNA polymerase. The optimal RAPDPCR reaction system was as follows a total volume of 25 μL contains 2.5 μL 10×Buffer, 1.8 mmol·L-1 Mg2+,2 U Taq DNA polymerase, 50 ng template DNA, 0.2 mmol·L-1 dNTPs and 1.6 μmol·L-1 primer. The reaction program fitting to the RAPD-PCR was as follows: initial denaturation at 94℃ for 2 min, followed by 5 beforehand cycles of 94℃ for 20 s, 36℃ for 30 s, 72℃ for 75 s; followed by 40 cycles of 94℃ for 20 s, 40℃ for 30 s, 72℃ for 60 s, and a final exposure to 72℃ for 20 min, then stored in 4℃. This RAPD-PCR system has some distinguising features including clear marker site, stable reaction system, reliable abundant polymorphisms, and better repeatability. It is suitable for the study on genetic diversity of E.chionantha.