The invention discloses application of aplysin in preparation of a medicine for treating glioma, aiming at researching the anti-tumor activity of aplysin to glioma. The MTT (Methyl Thiazolyl Tetrazolium) experiment shows that the inhibition ratio of aplysin to C6 cell is increased along with the raise of the concentration of aplysin; after the concentration is raised beyond 80mcg/m, the inhibition ratio of C6 cell does not raise obviously, namely, the most effective anti-tumor concentration of aplysin is 80mc/ml; the best effect appears in 48 hours in light of the action time; with the prolonging of the time, the cell inhibition ratio does not raise obviously. The animal experiment result shows that after the dose of aplysin is increased, the life time of a rat is prolonged, the weight of glioma is reduced, and the infiltration of lymphocyte is improved; 40mg/kg.bw is the best dose for reaching the best effect. The experiment shows that aplysin belongs to natural marine drugs and has small toxic and side effects, so that aplysin can be used as the medicine for treating glioma; aplysin is good in market application prospect.