Abstract: Objective To explore the plasma level of D-dimer in prastate cancer patients and its clinical significance. Methods The enzyme linked immunosorbent assay was used to measure the plasma level of D-dimer in 147 patients with prostate cancer（prostate cancer group）. The patients were followed-up for two year. The relationship between level of D-dimer and clinicopathological parameters（clinical stage，pelvic lymph node metastasis，distant organ metastasis，prostate specific antigen PSA level and Gleason score）along with prognosis were analyzed in patients with prostate cancer. Ninety-two patients with benign prostate disease（benign disease group）and 70 healthy men（healthy group）were enrolled as control. Results The plasma level of Ddimer of the prostate cancer group was（0.52±0.04） mg／L，higher than（0.26±0.08） mg／L of the benign disease group and（0.19±0.07） mg／L of the healthy group（P＜0.05）. The level of D-dimer was statistically different among different clinical stages，pelvic lymph node metastasis，distant organ metastasis， PSA level，Gleason score and prognosis（P＜0.05）. Compared with the corresponding items， there were higher levels of D-dimer in the items of Ⅲ-Ⅳ stage， with pelvic lymph node metastasis，with distant metastases， PSA level ＞20ng／ml，Gleason score ≥8 and death（P＜0.05）. ConclusionThe level of D-dimer elevated in patients with prostate cancer，and is closely related to clinical stages，metastasis and the level of PSA. It may facilitate the assessment of prognosis.