Abstract:The optimal culture conditions of the growth of Cymbidium sinense protocormsinduced from embryo were studied. The results showed that MS was the best basal mediumfor C. sinense protocorm growth and organogenesis. Treatment of 0.5 mg L-1 NAA incombination with 1.0 mg L-1 BA was most satisfactory for protocorm growth. When 1%sucrose and 0.1% activated carbon were added to the basal medium, a superior growth ofprotocorms was observed. Highest increase of the fresh weight of protocorms was at PH 5.0, Protocorms grew well under l5.5μmol m-2s-1 light intensity for 16 hours per day．Combined treatment with all optimal single factors mentioned above showed that the fresh weight of protocorms was 46％ higher than that of the control．As for the in crease of proliferation coeficient，dividing the protocorms by hands gave good result in cutting Inanner．