Abstract: The parameter character of chlorophyll fluorescence in micropropagated Ficus elastica plantlets of mini-cutting type and organ type were researched.The results showed that F_v/F_m of organ type were extremely lower than that of the mini-cutting type,but both of the most F_v/F_m and qN were the third back leaf,showing plantlets in vitro can still go on definite photosynthesis even if photosynthesis conditions were low very much.F_v/F_o,F_v/F_m and qN of organ type are extremely lower than that of the mini-cutting type,but F_o and F_m were on the contrary.The photosynthesis capacity of micropropagated plantlets was determined by the rooting condition itself.Therefore,to improve effectively photoautorophs capacity in explants depends not only on the concentration of dioxygen carbon and intensity of illumination,but also on culture medium composition,especially the function of plant growth regulation.To adjust illumination and cytokinin can reduce light damage and increase developing capacity of microprogated plantlets in organ type.