Abstract:DNA of Lilium brownii was extracted from the fresh leaves, silica gel dried leaves and scales. The optimized reaction system and programme of RAPD for Lilium brownii are as follows. The reactions were performed in a volume of 20 μl containing 20 ng of DNA, 2.0 mmol/L Mg2+, 0.2 mmol/L dNTPs, 1.5 U Taq DNA polymerase, 0.3 μmol/L primer (S1519). Thermal cycling was programmed by 1 cycle for 5 min at 94℃, followed by 35 cycles for 30 sec at 94℃, 50 sec at 38℃, and 1 min at 72℃ and finally, by 1 cycle for 10 min at 72℃, storing at 4℃.