The present invention relates to a pharmaceutical composition for the treatment of cancer comprising a chlorin e6-folic acid conjugate compound and chitosan, and more particularly, to a pharmaceutical composition for photodynamic therapy of solid tumors comprising the novel chlorin e6-folic acid conjugate compound or a pharmaceutically acceptable salt thereof and chitosan, in which the novel compound is prepared by linking chlorin e6 to folic acid, and effectively produces singlet oxygen in various media and has much better tumor selectivity than the known porphyrin-based photosensitizers, thereby being used effectively in photodynamic treatment for malignant tumors.