Objective To analyze family clustering of outpatient service utilization in rural areas of China.Method Outpatient service information of all families in rural area of sample county was obtained on the basis of new cooperative medical system (NCMS) outpatient database,and family outpatient service utilization database was cleared out with the help of functions like IF,LOOKUP and so on in Excel 2010.Lorentz curve was drawn by area graph and scatter diagram with Excel 2010,so was Gini coefficient.Descriptive statistic,variance analysis and so on were carried by IBM SPSS Statistic 20.0.Result 20％ family takes up 53％ of outpatient service,and rural family's Gini coefficient of outpatient service utilization is 0.516.Members of high outpatient service utilization family (HOUF) used (17.7) more outpatient service than other families (10.4,4.2).HOUF were mainly distributed in towns with high capability of township hospital and low capability of township hospital.Conclusion Great family clustering of outpatient service utilization exists in rural areas.Family homogenization is distinct,in which irrationality exists.The capability of primary medical institutions influences the outpatient service utilization of residents in rural area.