Objective:To investigate the predictive value of serumal retinol-binding protein 4(RBP4) level fro fetal macrosomia of non-diabetic pregnant women .Methods :The serumal levels of RBP4 of 500 non-diabetic pregnant women at 12 week ,20 week and 24 week of pregnancy were measured by immune projection turbidimetric method .Fetal macrosomia was defined as birth weight≥4000 g .The cut-off value ,sensitivity and specificity were calculated with receiver operating characteristic (ROC) curve .Results:Of the 500 non-diabetic pregnant women ,30 cases(6% ) got fetal macrosomia .The ROC curve showed that the predictive cut-off values of RBP4 at 12 week ,20 week and 24 week of pregnancy were 61 .0 mg/L ,50 .5 mg/L and 52 .5 mg/L , respectively ;the predictive sensitivity and specificity at 12 week ,20 week and 24 week of pregnancy were 42 .9% and 94 .5% , 70 .0% and 69 .5% ,76 .9% and 73 .2% ,respectively .The predictive cut-off value of RBP4 no later than 24 week of pregnancy was 51 .5 mg/L ;the predictive sensitivity and specificity were 61 .8% and 69 .5% .There was significant difference(P<0 .05) between the serumal level of RBP4 at 24 week of pregnancy in group fetal macrosomia and that in group nonfetal macrosomia . Conclusions :The predictive sensitivity of RBP4 increases in accordance with the increase of serumal level of RBP 4 .The serumal level of RBP4 of non-diabetic pregnant women at 24 week of pregnancy may have higher sensitivity and specificity in the predic-tion of fetal macrosomia .If the serumal level of RBP4 no later than 24 week of pregnancy is beyond 50 mg/L ,then the risk of fetal macrosomia will be higher .