The purpose of this study was to examine the effect of class walking on lifestyle activity. The subjects were recruited from the community around the university, and volunteered to eight weeks intervention. The intervention groups were 2 different walking program groups that included a class-walking group (A : n=32) and a voluntary walking group (B : n=31) ; and the control was a blood-pressure monitor group (C : n=22) . Only A group participated in a walking class with group instruction. Physical activity was measured by pedometer counts before the start of the intervention, during the 8-week intervention and again as follow up four months afterwards. In A group, the number of pedometer counts, during the group walking activity of the 5 th and 6 th weeks, was measured in order to evaluate the number of voluntary steps on the class-walking day. Although there was no significant difference among the three groups in daily activity before the intervention, the activity of A group (12367±3290) and B group (9988±3461) was significantly increased during the intervention. Also, there were significant differences between A and B, A and C. As for A group, the number of steps due to group walking (9025±584 steps) enhanced the daily activity on the class-walking days (16191±3988 steps), but significantly attenuated the voluntary steps on the class-walking days (7166±3988 steps), which did not significantly differ from the baseline of the daily activity. The number of steps on the non-class walking days (i. e. steps other than those taken on the class-walking day ; 11719±3454 steps) was not significantly different than that of B. There was significant enhancement of daily activity 4 months after the intervention for A (11487±4057) and B (9564±2545 steps), but not for C (9070±3485 steps), compared to the baseline. There was not a significant difference between the daily activity of A and B after the intervention. These data suggest that the instruction given and the steps taken in class walking enhance daily activity during the intervention period, and that voluntary steps play a more important role in whether or not one remains active and adheres to regular exercise.