Objective To study the clinical characteristics and risk factors of cow's milk protein allergy(CMPA)in infants less than 3 months old in Guangxi District.Methods From July 1 ,2012,to December 30,2014,infants less than 3 months old suspected of CMPA visiting the pediatric outpatient depart-ment of Maternal and Children Hospital of Guangxi Zhuang Autonomous Region were recruited,which included initial diagnosis and being transported from peripheral hospitals.Observation scale was formulated, attending physician screened patients and their senior made a definite diagnosis.All the infants underwent diagnostic algorithms and were followed up constantly.Results A total of 137 cases were divided into aller-gy group(n =51 )and control group(n =86).Two groups shared some common symptoms such as diarrhea, constipation,bloody stool,stomachache,gastroesophageal reflux(GER),indigestion,anorexia,feeding diffi-culties.Between the allergy group and control group the parameters such as feeding patterns (including breast feeding,mix feeding,formula feeding),improper deeding of food supplement,long-term use of antibiotics in neonatal period and parental atopy showed no significant differences(P ﹥0.05).The parameters in neonatal period including GER [20 cases (39.2%)vs.7 cases (8.1 %)],intake of cow's milk formula [51 cases (100%)vs.71 cases (82.6%)],feeding intolerance (including GER)[17 cases (33.3%)vs.1 1 cases (12.8%)],gut infection[8 cases(15.7%)vs.4 cases(4.7%)],transfusion of blood or/and bloody prod-ucts[12 cases(23.5%)vs.1 1 cases(12.8%)]showed statistically significant differences between the aller-gy group and control group(χ2 =19.538,P =0.000;χ2 =9.989,P =0.002;χ2 =8.308,P =0.004;χ2 =4.691 ,P =0.030;χ2 =5.198,P =0.023 ).Conclusion Symptoms of CMPA in infants no more than 3 months old involve mainly digestive system such as diarrhea,bloody stool,GER.Intake of cow milk formula in neonatal period play an important role in triggering CMPA.