Purpose: This study was to examine the effects of a obesity management program for obese children at a urban elementary school. Methods: The study subjects were fifty five 4<SUP>th</SUP>-6<SUP>th</SUP> graders (experimental = 29, control = 26) whose obesity indices were 120% or over fiunr two schools in a urban area. Obesity management program was conducted weekly 12 sessions with 60-day morning group exercises. Study instruments were Imbody 310 (BIOSPACE, 2005) and summated scales. Data were collected from April 6 to June 22, 2006 and analysed by descriptive statistics, X<SUP>2</SUP>-test and ANCOVA using SPSS/PC+ 14.0 program. Results: 1. Obesity management program was effective to reduce body weight (t = -2.54, p = .014), fat mass percent (t = -2.37, p = .021) and to increase muscle mass (t = 2.36, p = .022). And all these were also significant statistically in ANCOVA 2. Obesity management program were also effective to decrease level of obesity (t = -3.28, p = .002), and that of stress (t = -2.19, p = .033) and to improve food habit (t = 2.52, p = .016). And all these were also significant statistically in ANCOVA. Conclusion: School-based obesity management program for obese children was effective to reduce weight, fat mass percent, obesity, and stress; increase muscle mass; and improve food habit. School-based obesity management program, therefore, can be recommended as a health promotion measure in elementary school as curricular basis.