Obesity is viewed as one of the important public health problems of our times, and the velocity of propagation is highest in children. However, the composition of the intestinal bacterial flora may be a third element involved in the development of excess weight. The intestinal flora has links with intermediary metabolism and inflammation and may be involved in the pathogenesis of diabetes (types 1 and 2), metabolic syndrome and obesity. The aim of the present study was to characterize the composition of fecal flora in obese children, children with type 1 diabetes as compared with healthy children and to determine the possible relationship of fecal flora of children with the body mass index and glycemic level. Our microbial’s results the intestinal flora of obese children and diabetes’s children type 1 is different than others children who are with predominance of Lactobacillus and Enterococcus to obese children. A tripling of Staphylococcus bacteria was registered in obese children case by contribution to witnesses’ children. They also have high of Candida yeasts proportions. Significant correlations were found between the presence of these yeasts and BMI of obese children (p <0.05). All times Enterobacteriaceae are elevated in obese but not significant. The ratiois significantly higher between obese children and Healthy (p<0.0005)