Risk prediction models including the Prostate Health Index (phi) for prostate cancer have been well established and evaluated in the Western population.The aim of this study is to build phi-based risk calculators in a prostate biopsy population and evaluate their performance in predicting prostate cancer (PCa) and high-grade PCa (Gleason score ≥7) in the Chinese population.We developed risk calculators based on 635 men who underwent initial prostate biopsy.Then,we validated the performance of prostate-specific antigen (PSA),phi,and the risk calculators in an additional observational cohort of 1045 men.We observed that the phi-based risk calculators (risk calculators 2 and 4) outperformed the PSA-based risk calculator for predicting PCa and high-grade PCa in the training cohort.In the validation study,the area under the receiver operating characteristic curve (AUC) for risk calculators 2 and 4 reached 0.91 and 0.92,respectively,for predicting PCa and high-grade PCa,respectively;the AUC values were better than those for risk calculator 1 (PSA-based model with an AUC of 0.81 and 0.82,respectively) (all P ＜ 0.001).Such superiority was also observed in the stratified population with PSA ranging from 2.0 ng ml-1 to 10.0 ng ml-1.Decision curves confirmed that a considerable proportion of unnecessary biopsies could be avoided while applying phi-based risk calculators.In this study,we showed that,compared to risk calculators without phi,phi-based risk calculators exhibited superior discrimination and calibration for PCa in the Chinese biopsy population.Applying these risk calculators also considerably reduced the number of unnecessary biopsies for PCa.