Abstract： Objective To investigate the anti-tumor effects of a combination of Kanglaite injection (KI) and photodynamic therapy (PDT) on human pancreatic cancer SW1990 xenograft in nude mice.Methods The animal model of human pancreatic cancer was developed by suturing small pieces of SW1990 tumors into the dorsum of nude mice.60 rats were randomly divided into six groups:group A ( control group without treatment),group B ( receiving 1.25g/kg KI via the tail vein prior to PDT and continuously for 10 days),group C (receiving 2.5g/kg KI via the tail vein continuously for 10 days),group D (PDT group,2 mg/kg Photosan 48h prior to laser irradiation),group E ( group B + group D),group F ( group C + group D)with 10 rats in each group.The tumor sizes were measured twice per week.The mice were sacrificed on the 14th day of PDT treatment.The tumor was took out and weighted and the tumor inhibitory rate was analyzed.Results The tumor volumes of group A to F were 9550.08±52.46)mm3,(519.71±46.44)mm3,(405.29±38.67 ) mm3,( 199.27±37.37) mm3,( 107.47±14.13 ) mm3 and (75.58±12.53 )mm3,the weight of group A to F were (0.82±0.08)g,(0.77±0.06)g,(0.61±0.06)g,(0.41±0.05)g,(0.28±0.04)gand (0.16±0.04)g,respectively.The tumor volumes and tumor weights of the two combined groups were significandy smaller than those in the other groups (P＜0.05).The combination group of 1.25 g/kg KI increased the tumor inhibitory rate from 50% in PDT group to 65.9%.The combination group of 2.5 g,/kg KI increased the tumor inhibitory rate to 80.5%.Conclusions KI had attenuated effect on PDT therapy,and the combination of KI and PDT could significantly inhibit the tumor growth.