Objective:To investigate the two-dimensional and Doppler echocardiography in the left renal vein entrapment syndrome(nutcracker phenomenon,also known as)the diagnosis.Methods:The clinical diagnosis of 22 cases of patients with nutcracker two-dimensional and doppler ultrasonography,when measured in supine position before the expansion of left renal vein stenosis proximal parts (a paragraph) and the narrow part of (b above) diameter.Calculation of left renal vein and inferior vena cava pressure difference between the △ P = 4 (V22-V12).Results:The left renal vein in supine position and the expansion of the narrow part of the Department of the ratio (a / b) 3 times;left renal vein and inferior vena cava pressure difference between the △ P ≥3 mmHg(normal △ P <1 mmHg).Conclusions:CDFI and PD can be a direct reflection of left renal vein and inferior vena cava pressure difference between the,two-dimensional combination of B-and doppler in the diagnosis of nutcracker phenomenon provides more evidence can be used as criteria for diagnosis of the disease