Abstract: According to their existing form, ideas fall into two categories: individual ideas and collective ideas. When disseminated to a certain extent, individual ideas turn into collective ones through individual awareness, collective imitation and social opinions. Widely accepted by group members, collective ideas bring free individuals together into a cohesive community. Restraining the behaviors of community members, collective ideas enable community members to conduct consistent actions, which is essential to an institution. The change of collective ideas is the sign of institutional transition, and it can also direct institutional transition. When collective ideas start to change, original institutions will no longer adapt to the changed collective ideas. At this time, institutions and collective ideas will weaken each other, and collective ideas will promote the change of the existing institutions and the birth of new ones