The contents of soluble sugar and soluble protein as well as PPO,POD and CAT activities in above-ground part of Huperzia serrata(Thunb.ex Murray) Trev. under different illumination conditions were analyzed. The results show that with the treating time(18 d) prolonging, these indexes appear different changing trends under different illumination conditions, and most of them are higher than those before treating. Soluble sugar content, soluble protein content, PPO activity and POD activity of H. serrata in 2 400 and 3 600 lx groups are obviously higher than that in 1 200 lx group, but CAT activity among the three illumination groups has no significant difference. It is concluded that the relative high illumination has a certain influence on some physiological-biochemical indexes of H. serrata, low illumination(1 200 lx) is relatively suitable for H. serrata growth.