【Abstract】 Objective To investigate the relationship between ERG protein expression in diagnostic specimens and progression for prostate cancer during active surveillance. Methods 56 patients diagnosed prostate cancer following active surveillance during March 2012 to February 2016 were recruited into the study. Parameters such as age at diagnosis, prostatespecific antigen (PSA) level at diagnosis, Gleason score (GS), clinical stage were collected retrospectively. ERG protein expression was detected by immunohistochemistry. Relationship between ERG expression status and clinicopathological characteristics was analyzed. Kaplanmeier survival model and Cox proportional hazards regression model were used to investigate the predicative roles of ERG status and clinicopathological characteristics for progression of prostate cancer during active surveillance.Results 48 patients completed the final followup, and 375% of the patients were found ERG protein positive (18/48). Kaplanmeier survival model shown the median histological progression free survival time were 32 months and 48 months（(2=4476，P=0.034）. The median PSA progression free survival time were 21 months and 26 months for ERGpositive group and ERGnegative group, respectively（2=4272，P=0.039）. ERG positive was a independent predictor for prostate cancer progression during active surveillance in Cox regression (Hr=2024,P=0.044). Conclusion The expression of ERG protein increases the risk of prostate cancer progression during active surveillance. ERG protein status can be used to individualize active surveillance programe.