The antitumor experiment on bilateral 4T1 murine breast cancer model demonstrated that PpIX-NLG@Lipo mediated PDT could damage tumor cells directly to inhibit the growth of primary tumor, and simultaneously present tumor-associated antigens to stimulate the host immune system, then PpIX-NLG could inhibit IDO pathway to achieve effectively distant tumor inhibition. This evidence concerns the gene IDO1 and breast carcinoma.