“Rituals” are activities having typical context，accompanied by the repetition of the act，and can provoke participants’ specific emotional reaction. Activities similar to rituals in the daily life can be called “ritual-like” activities. Based on the study of eleven square dancing groups in Shanghai，this paper explores the formation and cohesion mechanism of ritual-like groups. Firstly，most of the participants are facing the transition from the work stage to retirement stage during their life passage. In this process，they need space to interact with others and create new social relations. As a context with “ritual-like” features，“Square dancing” is a proper space，which promoted the generation of square dancing groups. After the generation，based on different mechanisms of comparison and identity，different types of square dancing groups completed their cohesion process. Particularly，based on the empirical study，this paper indicates that the intragroup symbolic boundaries have signiticant ettects on the cohesion and development of ritual-like groups.