This paper verified sphere nature observed in community activities of citizens' activity group. It also explored the effect on community activities by municipal merger. Main results are as follows:
1. From the relationship between motive of establishment, opportunity of establishment, setting reason for the ranges of activities, and ranges of activities it was possible to grasp sphere nature by each aspect.
2. By difference of the basic attribution, specific motive of establishment, scope of ranges of activities, the effect of municipal merger tends to be different.
3. Also, it was possible to explore sphere constituted by the development from the inside of region.
