Objective To establish a patient-derived gastric cancer xenograft(PDX)model in nude mice and to investigate the application of near infrared fluorescent (NIRF)dye IR-783 in in vivo imaging of gastric cancer xenograft models. Methods Fresh human gastric cancer tissue was taken and transplanted into the subrenal capsule of nude mice to establish the xenograft model.When the transplanted tumors grew,took part of the tumor tissue to do HE staining and compare the structural characteristics with the primary tumor.Another portion of the tumor was xenografted into nude mice subcutaneously.Twenty days later,the tumor-bearing mice were injected intraperitoneally with IR-783 dye (10μM) in a dose of 100 mg/20 g. The intensity of the tumor image was monitored by optical NIRF imaging. The correction between tumor volume and fluorescence intensity was analyzed.Finally,the expression of OATP1B3 and HIF1α in the xenografted tumor tissue was detected by immunohistochemistry. Results We successfully established three patient-derived xenograft (PDH) models of human gastric cancer. The transplanted tumor tissues maintained the histological characteristics of the primary tumor well. NIRF signal can be detec ted in subrenal capsule of the xenografted nude mice. The correlation between tumor size and fluorescence intensity in the PDX models reached higher than 98%. Strong positive expressions of HIF1α and OATP1B3 in the tumor tissues were detected. Conclusions NIRF dye IR-783 can be specifically accumulated at the tumor site,therefore, can be used to detect PDX in vivo early.The tumor targeting property may be related to the expression of OATP1B3 and HIF1α.