臺中縣市合併之前，彼此議會的運作生態截然不同。原臺中縣議會是以紅黑派系所主導的次級團體為議事運作的主體；而原臺中市議會則是以黨團運作為主。但在2010年縣市合併升格為直轄市後，原本縣市不同的議會運作生態，因合併而產生磨合，在泛藍陣營形成次級團體與黨團併行的局面。由於地方派系最重要的目標，就是要爭取公部門職位，從中汲取資源，轉化成派系的資源，以壯大派系勢力，將派系利益極大化就是派系間的行事法則。因此，本文將著重在探討臺中縣派系如何透過議會次級團體，將其「利益極大化」。基於此，本文乃以「次級團體之形成」、「次級團體與國民黨團之互動」與「次級團體運作之效果」等三個面向作為研究架構，觀察派系運用何種手段，將其「利益極大化」。此外，觀察合併後的臺中市議會可以發現，雖然目前仍維持「紅黑共治」的情況，但此種由派系決定資源如何分配的情況已有所轉變，未來資源分配的重點將由追求紅黑之間的派系平衡，轉變為追縣市之間的區域平衡。

The Taichung City Council and Taichung County Council were governed by two contrasting political entities before the merger of the two administrative regions in 2010. Caucus is in effect in the former, while the latter was predominantly run by sub-groups consisting of the red and black factions. However, a watershed moment had been reached as the two regions merged to become a special municipality in 2010. Yet, due to the change in political ambiance, what followed was a series of skirmishes. The pan-blue camp at the end formed the sub-group parallel to the caucus. The most important aim of local factions is always to win public sector positions, extract resources which will then be converted to the resources of their factions, and finally strengthen factions’ power. Maximizing the interests of the faction, after all, is the guiding principle.. Therefore, in this study, how the factions from Taichung County maximize their interests through council sub-groups is explored. Furthermore, this paper studies how factions maximize their interests from three aspects: ＂the formation of sub-groups,＂ ＂the interaction between sub- groups and Kuomintang,＂ and ＂the effect of sub-groups’ operation＂. In addition, even though ＂red-and-black co-governance＂ remains to be apparent in the Taichung City Council after the merge, how factions decide to allocate resources has changed. In the future, resource allocation will be done so to pursue regional balance between the old Taichung City and Taichung County, instead of pursuing a balance between the red and black factions.