八輕的興建由於具備提振經濟發展的功能，受到熱烈歡迎；卻也因為其對環境生態影響甚鉅，引發當地居民的反對聲浪，以及全國各地的環保團體串連抗議，導致進度延宕。這種經濟與環保衝突的鄰避型設施，在廠址的選擇上，因為必須要滿足社會大眾的需求，而成為環境決策相當重要的一環。只是，同樣渴望經濟發展的雲林縣與嘉義縣，為何八輕最後會選擇落腳雲林而非嘉義？決策過程中的利害關係人又是如何互動？研究結果發現，雖然政商聯盟在中央決策場域上佔有優勢，然廠址抉擇的關鍵仍在於地方的政治生態。嘉義黃林兩派對立的政治生態，讓主政黃派在爭取開發案上，因受到林派為反對而反對的掣肘，中油倍感經營不易而退出；在雲林張派獨大的情形下，沒有足以抗衡的反對勢力，而有利於八輕的進駐。此外，無論在中央或地方的層級，環保團體都企圖在政治力的夾縫中求生存，以阻擋政商聯盟的不正義開發。地方民眾則因利益不同而選擇與派系或環保團體結盟。 / The building of 8th Naphtha Cracking Project is so popular because of its function of promoting economic development. However, local residents have great opposition to it because of its giant influence on environment. Furthermore, the series of representations from the environmental groups have made the work progress at a very low pace. The siting of nimby facility which causes the conflict between economic development and environment protection has become an important part of decision making because it has to satisfy all kinds of needs in the society. Then, we may wonder why 8th Naphtha Cracking Project chooses Yun-lin County instead of Chia-yi County since both of them are eager to develop their own economics, and how the stakeholders interact during the decision making process. The study finds out that politicoeconomic coalitions control the national political arena, and they seem to monopolize decision making process. But the local political ecology is the key to siting. In Chia-yi County, Huang Faction is in confrontation with Lin Faction. Although Huang Faction makes efforts to win the developing project, Lin Faction just protests without particular reasons. Finally, CPC gives up the project because it is so difficult to run business in this situation. On the other hand, Chang Faction is so dominant that there is no political opposition movement in Yun-lin County. And that fosters the coming of 8th Naphtha Cracking Project. In addition, no matter in central or local level, environmental groups try to influence policy to prevent the unjust development from politicoeconomic coalitions. And the local residents enter into strategic coalitions with factions or environmental groups due to different interests.