The authors present main results of a survey, aiming to understand the influence of various phenomena on community organization, as it can be observed in Quebec, in the 1990’s and at the beginning of the 2000’s. They focus on two aspects of structuration: transformation of community organization between 1988 and 2004, and its differentiation in the public and in the third sectors. Data were collected through a survey, and statistical analysis show many differences between groups of respondents. The discussion reveals that structural phenomena (such as social policy, social movements’ actions, characteristics of workplace, community organizers’ profile, and offer of continuous training) and reflexive phenomena (improved knowledge of community organizers and mobilization in professional association) explain how community organization is transformed and differentiated.