Objective To explore the cause, diagnosis, and treatment methods of portal vein thrombosis （PVT） after splenectomy. Methods The clinical data of 29 patients who were got splenectomy because of portal hypertension or traumatic splenic rupture from August 2002 to August 2008 in our hospital were analyzed retrospectively. Results Tweenty-seven patients with PVT were treated successfully, whose thrombi were absorbed completely or partially. One case died of peritonitis，septic shock，and multiple organ failure. One case died of hematemesis, hepatic coma，and multiple organ failure. Tweenty-four patients were followed up, the follow-up time was 0.5 to 3 years, the average was 2 years. Two cases died of massive hemorrhage, 1 case died of hepatic encephalopathy，and 1 case died of liver failure. Two cases occurred deep venous thrombosis in one year after treatment, and the remaining patients had no recurrence of venous thrombosis. Conclusions PVT have some connection with the raise of blood platelet and the hemodynamic changes of the portal vein system after splenectomy. Standardization of operation, early diagnosis, early line anticoagulant，and antiplatelet adhesion therapy are effective way to prevent and treat PVT.