Abstract: A total of 50 rubber tree (Heveae brasiliensis) clones were chosen, which field identification and indoor identification inoculated by purified powdery mildew (Oidium heveae) to evaluate the clone's resistance level. The result showed that the resistancesusceptibility diffirence of rubber tree clones was distinct: resistance (6 clones), mid-susceptibility (26 clones), susceptibility (13 clones),and high susceptibility (5 clones). The result of indoor identification was correlated with field one significantly. Meanwhile, the lengths of hypha were from 26.90 to 53.22μm.