Reactive stromal changes in prostate cancer(PCa) are likely involved in the emergence of castration?resistant PCa(CRPC). This study was designed to investigate stromal changes in patients with clinically advanced PCa and analyze their prognostic signiifcance. Prostate needle biopsies obtained from 148patients before castration therapy were analyzed by Masson trichrome staining and immunohistochemical analysis of vimentin and desmin. Reactive stroma grading was inversely correlated with Gleason score. Stroma grade (Masson stain 82.8%vs 45.6%,P<0.001) and vimentin expression(P=0.005) were signiifcantly higher, and desmin expression (P=0.004) signiifcantly lower, in reactive stroma of tumors with a Gleason score of 6–7 than in adjacent peritumoral tissue. Kaplan?Meier analysis showed a signiifcant association between reactive stroma grade in tumors and the occurrence of CRPC in patients with a Gleason score of 6–7(P=0.009). Furthermore, patients with higher vimentin or lower desmin expression had a shorter disease?free period. In multivariate analysis, only vimentin expression was a signiifcant predictor of tumor relapse (hazard ratio 1.78, 95% conifdence interval 1.12–10.26,P=0.012). These ifndings indicate that the intensity of reactive stroma is associated with castration responsiveness, especially in patients with a lower Gleason score where the abundant stroma component is most frequently found. High expression of vimentin in tumor stroma was independently associated with poor outcomes in patients with Gleason scores of 6–7, and may serve as a new prognostic marker in daily practice.