The purpose of this study was to analyze the concept of physical activity. The method was based on the steps of concept analysis by Walker and Avant(l988). The result of this study were as follows ; Upon the concept analysis, physical activity is defined as a series of bodily movements which is performed voluntarily by individual. The defining attributes of physical activity were a series of bodily movements, energy expenditure, goal-directedness, and self-control of the body. The antecedents of physical activity were neuromusculoskeletal function, cardiopulmonary function and cognitive function. And the consequences of physical activity were improvement of physical function, induction of fatigue, and need(physiopsychosocial) satisfaction. Further studies are needed to develop the concept of physical activity using the Hybrid model. In addition. considering personal characteristics it is important to study the facilitating factors of physical activity.