Objective To investigate the autophagy of osteosarcoma MG63 cells induced by aloe emodin-mediated photodynamic therapy, and to discuss the relationship between autophagy and apoptosis. Methods The cultured MG63 cells were divided into 4 groups: empty control group, AE group, LED group, and AE-PDT group. MG63 cells in AE-PDT group were treated with aloe emodin combined with photodynamic therapy. The cell viability was measured by CCK-8, the DCFH-DA probe was used to detect cell ROS level, the autophagosomes were examined by MDC staining and electron microscope, the apoptosis of MG63 cells was detected by flow cytometry, and the autophagy-related protein (LC3 and Beclin-1) expressions were assessed by Western blotting analysis. Results Photosensitizer aloe emodin-mediated PDT significantly suppressed cell viability in a photosensitizer concentration- and energy density-dependent manner. The ROS level and autophagosomes were significantly increased in the AE-PDT group, with classical autophagosomes found under the electron microscope. AE-PDT induced autophagy and apoptosis of MG63 cells. The apoptosis rate was significantly increased when autophagy was inhibited by 3-MA (P<0.05).The results of Western blotting analysis showed that ratios of LC3-Ⅱ/LC3-Ⅰ and Beclin-1/β-actin in AE-PDT group were higher than those in the single AE treatment group, single light irradiation group, and the empty control group. Conclusion AE-PDT can induce autophagy in the MG63 cells. At the early stage of AE-PDT treatment, autophagy can postpone apoptosis and hence exert a protective effect.