Objective To explore the nutritional status and influencing factors in children under 5 years old,and to establish the foundation of health condition for these children. Methods A total of 4 221 children aged 0～5 years were selected by stratified random sampling in Guiyang.Physical growth was assessed and the participants' parents were surveyed using questionnaires by face-to-face interview.And data were analyzed with SPSS17.0 statistical software. Results The prevalence rates of malnutrition and obesity in children under 5 years old in Guiyang were 7.37%and 2.42%,respectively.The risk factors of malnutrition were associated with living in rural areas,upper respiratory tract infection,non-breastfeeding within six months,independent feeding,frequent snacking and low level of mother education. Conclusions The prevalence rate of malnutrition among children aged 0～5 years in Guiyang is high.An effective intervention strategy should be provided by relevant government and pediatricians.