Objective To investigate the effect of short-term intensive training on body composition in children with simple obesity. Methods All the obese children were selected from participating in the weight loss summer camp of Zhengzhou Children's Hospital in July 2012 and 2013,including 28 males and 32 females,aged 8 years and 6 months to 14 years old.Weight loss program was including aerobic exercise,proper diet.Aerobic exercise program was designed according to different children of different treatment options,using the principle of gradual and orderly progress,and gradually achieve weight control requirements.The body composition and height,weight,BMI,body water,protein,inorganic salt,fat,body fat percentage,muscle were analyzed in children with simple obesity before and after training.SPSS 16.0 statistical software was used for the above data,paired t-test before and after weight training. Results After 3 weeks of training,weight[(64.97±17.89) kg,BMI (27.42±5.24) kg/m²],fat[(26.68±10.88) kg],body fat percentage[(39.49±9.38%)]were significantly lower than those in before training[weight (68.06 ± 20.19) kg,BMI (29.09±6.41) kg/m²,fat (30.02±12.22) kg,body fat percentage (42.40±8.61)%](P<0.05),while height[(152.64±10.28) cm vs (151.61±10.15) cm],inorganic salts[(2.70±0.66) kg vs (2.61±0.65) kg]were significantly increased (P<0.05),but the water in body[(28.07±6.27) kg vs (27.98±6.72) kg],protein[(7.50±1.68) kg vs (7.45±1.80) kg],muscle[(20.67±5.06) kg vs (20.50±5.44) kg]were no significant changes (P>0.05). Conclusions Short-term intensive training can effectively control the weight through reduced fat in obese children,but is also conducive to the enhancement of children's height and physique enhancement.