Objective To evaluate the reliability and validity of breastfeeding family support questionnaire.Methods The questionnaire was designed by referring to literatures and collecting suggestion from nursing experts.Questionnaire items were assessed by 5 experts especially in the maternity,midwifery education and familiar with breastfeeding field,then items were revised.Data were collected from 100 primiparas in a first-class hospital with the questionnaire.The construct validity was evaluated by exploratory factor analysis and Cronbach' s α coefficients were estimated to investigate the homogeneity reliability.Results Exploratory factor analysis revealed that the questionnaire contained two factors:psychological support (factor 1) and behavior support (factor 2).These factors accounted for 70.04％ of the variance.The correlation coefficient of the questionnaire was 0.886.Among 100 primiparas,7th day after discharge,the breastfeeding rate was 31％,perceiving family support was moderate degree (2.67 ± 0.45),family support score of taking breastfeeding primipara (2.99 ± 0.49)was significantly higher than that of taking mixed feeding (2.72 ± 0.30) and artificial feeding person (2.28 ± 0.27).Conclusions The reliability and validity of the breastfeeding family support questionnaire is good and the questionnaire could be used as an effective tool to measure the status of the family support on breastfeeding of the primiparas.