Abstract: The adventitious buds were induced from in vitro leaves of Rhododendron delavayi var. delavayi using NAA combined with TDZ or ZT，and morphological and histocytological studies were observed on the regeneration process. The results showed that TDZ was more effective than ZT in the induction of adventitious buds from the leaves of R. delavayi var. delavayi，and that WPM + TDZ 0.08 mg • L-1 + NAA 0.01 mg • L-1 was the best medium for adventitious buds regeneration. The differentiation rate was 83.33% and the number of sprouts per leave was 4.29. Its regeneration belonged to the direct occurrence of organs with multiple origins. The regeneration process underwent four key stages of cell proliferation，cell dedifferentiation，cell differentiation，bud primordium formation and development.

Key words: Rhododendron delavayi var. delavayi, in vitro leaf, adventitious bud, histocytology, TDZ, ZT