本研究以台灣鋼筋產業為研究對象，運用產業組織理論中之結構－行為－績效（SCP）分析架構，探討市場結構、廠商競爭行為與產業績效之互動關係，以解析在國際原物料波動、房地產與公共工程需求循環，以及ESG與減碳政策趨勢下，台灣鋼筋產業之競爭邏輯、轉型壓力與發展方向。 研究結果顯示，台灣鋼筋產業屬「高集中度、中度競爭」之典型寡占市場，前四大鋼廠市占率約51%，並具產品高度同質性、區域市場分割及資本、能源與環保法規形成之進入障礙，產業競爭主要建立於規模經濟、區域布局與制度性定價機制，而非完全價格競爭。於廠商行為方面，市場長期存在由主要鋼廠主導之週期性價格訊號制度，其餘業者多採跟隨策略，形成領導－跟隨之策略互動模式，價格亦深受廢鋼成本、能源價格與市場預期影響。 在產業績效方面，鋼筋產業之獲利與競爭優勢主要取決於原料採購能力、產能利用效率、能源管理及下游整合程度。由於鋼筋屬高同質性產品，短期需求價格彈性偏低，價格波動多由供給端成本驅動。在淨零排放、碳費制度與綠色供應鏈要求持續提升下，電弧爐（EAF）製程之低碳排優勢將逐步由成本優勢轉化為制度性競爭優勢，並成為影響產業長期競爭力與市場地位之關鍵。;This study examines Taiwan’s rebar industry through the Structure–Conduct–Performance (SCP) framework of industrial organization theory to analyze the interactive relationships among market structure， firm conduct， and industrial performance. The research aims to explain the competitive logic， transformation pressures， and future development trajectory of Taiwan’s rebar industry under conditions of international raw material price volatility， cyclical fluctuations in real estate and public infrastructure demand， as well as the growing influence of ESG and decarbonization policies. The findings indicate that Taiwan’s rebar industry represents a highly concentrated， moderately competitive oligopolistic market. The top four steel manufacturers collectively account for approximately 51% of market share. The industry is characterized by high product homogeneity， regional market segmentation， and significant entry barriers arising from capital intensity， energy dependence， and environmental regulations. Consequently， competition is primarily based on economies of scale， regional deployment， and institutionalized pricing mechanisms rather than pure price competition. In terms of firm conduct， the market has long operated under a cyclical price-signaling system led by major steel producers， while other firms generally adopt follower strategies， forming a leader–follower strategic interaction pattern. Pricing behavior is strongly influenced by scrap steel costs， energy prices， and market expectations. Regarding industrial performance， profitability and competitive advantage in the rebar industry are largely determined by raw material procurement capability， capacity utilization efficiency， energy management， and downstream integration. Due to the highly homogeneous nature of rebar products， short-term price elasticity of demand remains relatively low， and price fluctuations are predominantly driven by supply-side cost factors. Under the accelerating trends of net-zero emissions， carbon fee systems， and green supply chain requirements， the low-carbon advantage of Electric Arc Furnace (EAF) production is expected to gradually evolve from a cost advantage into an institutional competitive advantage， becoming a critical determinant of long-term industrial competitiveness and market positioning.
