Objective To investigate the ultrasound characteristics,etiology and prognosis in hydrops fetalis.Methods From September 2002 to May 2010,156 hydrops fetalis presented in Shenzhen Maternity and Child Healthcare Hospital were studied retrospectively,including ultrasound characteristics,etiology,and prognosis.Results All of the 112 typical hydrops fetalis,20 cases with isolated ascites,8 cases with isolated pleural effusion,7 cases with isolated pericardial effusion,5 cases with isolated subcutaneous edema,4 cases with isolated placental thickening were observed by ultrasonography.The major etiology and associated diagnosis consisted of 35.9％ (56/156) of non-immune anemia,9.6％ (15/156) of cardiac abnormalities,7.1％ (11/156) of intrauterine infection,6.4％ (10/156) of twin problems,5.8％ (9/156) of meconium peritonitis,5.1％ (8/156) of thoracic-lung disease,4.5％ (7/156) of chromosomal abnormalities,1.9％ (3/156) of immune anemia.Alpha thalassemia was the most common non-immune anemia (96％,54/56).An etiology and associated diagnosis could be determined in 81.4％ ( 127/156 ) of cases.Follow-up data showed that 7 cases were fetal death,110 women elected to terminate their pregnancies,3 cases lost follow-up,the other 36 cases preserve continuing pregnancy,including 28 liveborn infants and 8 fetal deaths.Etiology of twin-twin transfusion syndrome,meconium peritonitis,congenital chylothorax,intrauterine infection,cardiac abnormalities and so on had survived fetuscases.The survival rate of typical hydrops fetalis in the present series was 3.6％ ( 4/112 ).Conclusions Ascites is the most common characteristics of sonogram in hydrops fetalis.The etiology of hydrops fetalis is extremelycomplex.The prognosis is associated with the etiology and hydrops subtype.