Abstract: Objective To study the changes of portal system hemodynamics and its relationship with degree of esophageal varices by color Doppler ultrasonography in cirrhotic patients. Methods 80 cirrhotic patients were divided into mild, moderate and severe groups according to the degree of esophageal varices. 30 healthy controls were included in the study. The blood flow hemodynamics including diameter (D) , blood flow velocity (V) , and the blood flow volume (Q) of portal vein (PV) , splenic vein (SV) , superior mesenteric vein (SMV) and left gastric vein (LGV) were measured by CDFI. Results The blood flow velocity of PV, SV and SMV was much lower whereas the blood flow velocity of LGV was much higher, and the diameter of PV, SV, LGV and SMV was much wider in cirrhotic patients than the healthy controls. The ratio of the patients QSV/QPV was 54.5%, which was higher than 30.3% of the control group. With the increasing degrees of esophageal varices the DPV was wider, the VPV was slower, and the DLGV, VLGV and QLGV were significantly increased. Red symptom was found in all severe group patients and in about 92.3% (36/39) of degree-2 group. Flow direction of LGV in the cirrhotic patients was hepatopetal in 81.25%, to-and-fro state in 5.0%, hepatofugal in 13.75% and hepatopetal in the healthy control group Flow direction was hepatofugal for 94.9% patients in the severe group. Conclusion The PV, SV, SMV and LGV indexes were highly sensitive and specific parameters for the diagnosis of the degree of esophageal varices by Doppler ultrasound. Therefore, the hemodynamics analysis by Doppler ultrasound may serve as the noninvasive parameter for early diagnosis of esophageal varices.