The technology of branch diameter - cut was applied to study seedling - raising on Elacocarpus Decipiens Hems1,which could improve rooting ratio of Elacocarpus Decipiens Hemsl. The results of the study indicated that rooting ratio of scion cutting was 90% with pre - treatment by KOH, the optimum combination could reach 97%. Through variance analysis, it showed obviously variance comparing with non pre - treatment. It was an ideal way for vegetative propagation to use branch diameter cutting with non pre - treatment and hormone treatment.