Environmental Impact Assessment (EIA) provides an effective mechanism for prevention of potential environmental pollution and for coordination in collaborative decision-making situations. The desire to stop cases of improper development has made EIA a required mechanism in many countries. The essence of EIA is an opening procedure of investigation, assessment, deliberation, and citizen participation. Despite the fact that there has been an official design of citizen participation in Taiwanese EIA system since 1995, the design remains unpopular and untrustworthy in our society due to problems such as inefficiency, political complexity, etc. In this paper, we explore fundamental problems of the current design of citizen participation in the EIA system and describe our aims in managing these problems via thorough studies of thirty EIA cases and a public opinion interview of interest parties. We focus on a more open and more effective process for operating citizen participation and then suggest future directions based on results of the interview.