Objective Idiopathic venous thromboembolism（VTE）has high prevalence，risk and recur⁃ rence. The purpose of this study was to investigate whether prolonged anticoagulation can reduce the incidence of VTE outcome events. Methods We selected 306 patients diagnosed with idiopathic VTE in Kailuan General Hos⁃ pital，from January 1，2013 to December 31，2016. All the patients（aged 24 to 85 years）with anticoagulation for 3 months were randomly divided into conventional anticoagulant group and prolonged anticoagulant group with a follow⁃ up of36 months. The primary outcome event was the recurrence of VTE and secondary outcome events were bleed⁃ ing，including major bleeding and clinically related non ⁃ major bleeding. Results A total of 306 VTE patients were included in the analysis，with a mean age of（61.54 ± 11.54）years and 184 males（60.13%）. In the conven⁃ tional anticoagulation group（n = 155），there were 45 VTE recurrence，3 major bleeding，and 21 clinically relevant non ⁃major bleeding；in the prolonged anticoagulation group（n = 151），there were 8 VTE recurrence，5 major bleeding and 30 clinically relevant non⁃major bleeding. Prolonged anticoagulation therapy significantly reduced the incidence of VTE recurrence when compared with conventional anticoagulation therapy（log⁃rank test，P < 0.000 1）， and no significant increase of major bleeding and clinically relevant non ⁃major bleeding（log ⁃ rank test，all P = 0.458 8）were observed. Prolonged anticoagulation therapy significantly reduced the risk of VTE recurrence com⁃ pared to conventional anticoagulation therapy（HR = 0.44，95%CI：0.19 ~ 0.99）. Moreover，prolonged anticoagula⁃ tion therapy didn′t increase the risk of major bleeding and clinically relevant non⁃major bleeding in VTE，with HR （95%CI）of 1.00（0.24，4.19），1.71（0.83，3.51），respectively. Conclusion The recurrence rate of VTE patients in the prolonged anticoagulant group is lower than that in the conventional anticoagulant group，and the incidence of major hemorrhage and clinically related non⁃major hemorrhage donot increase. The prolonged anticoagulant therapy has high application value for preventing the recurrence in patients with idiopathic VTE.