Objectives: The objectives of this study is the examination of physiology of the obesity by automatic bioelectric response recorder Methods: The 86 patients below BMI 20 and the 144 patients over BMI 25 were objectives. They visited Dongguk University Kangnam oriental medical hospital from 2000. April 1 to 2001 August 30. Results: The patients below BMI 20 were accelerated a parasympathetic nerve and were decelerated a sympathetic nerve, so they loosened the tension, lacked the resistance and were oversensitive. The patients over BMI 25 were accelerated a sympathetic nerve and were decelerated a parasympathetic nerve, so they maintained the tension and the resistance.