Abstract: BGC823 human stomach cancer cells were cultured for the identification of photodynamic effects of Cortex phellodendri with illumination of 480 nm and 650 nm wave length. In the test groups with illumination, the herb extract diminished cell growth curve and the metabolism of 3-(4,5-dimethylthiazo1-2-yl)-2,5-diphenyl tetrazolium bromide(MTT). Futhermore, the significant decrease of the acid phosphatase (P<0.01) and the incorporation of ³H-TdR into cells (P<0.01) were demonstrated in the test groups.The progression of cancer cell cycle was postponed in S-phase(P<0.01) by the herb of 100 mL/L,but no chromosome adhering aberration appeared. The ultrastructural appearances showed that in the test groups, the mitochondria and the rough endoplasmic reticula of the cells became swollen and vesiculate and the ribosomes decreased.The result showed that Chineses medicine Cortex phellodendri has photosensitive effects on the cancer cells.

Key words: Chinese medicine Cortex phellodendri, photosensitive anticancer, cytological mechanism