台灣加入WTO後，面對市場的開放與自由競爭，傳統產業的競爭力與生存受到極大的挑戰，本研究以與日常民生息息相關的傳統產業－水泥業之8家上市公司做為研究對象，就水泥反傾銷銳課徵前後期間（1998年至2005年）進行產業的經營效率評估。此採用資料包絡分析法分析整個水泥產業與個別廠商於受傾銷前後期間之經營效率與效率變動及Malmquist生產力變動的情形，街量傾銷前後經營效率的表現。 整體水泥產業現況，其生產力與生產技術均有進步，且傾銷後較傾銷前佳。雖然其技術效率不彰，但在生產技術的大幅改善下，並不影響整體生產力的進步。另就技術效率觀察，整個研究期間之技術效率衰退，主因傾銷前純粹技術效率的退步與傾銷後規模效率的衰退所致。換言之，管理效率不彰、規模效率的衰退為技術效率衰退之主因。經實證發現此一因素係因廠商企業結構之改變，導致規模效率與技術效率為無效率所致。 整個研究期間與傾銷前水泥廠商之效率值中，具有效率的單位近1/3，無效率的單位有5個，這5個單位之平均效率值達99.1%，其經濟上之意義即多浪費了0.9%的資源。此外傾銷後之無效率的單位有6個，平均效率值達99.13%，其經濟之涵義為多浪費了0.87%的資源。可見即使傾銷後之無效率單位較傾銷前多，但在資源使用上，事實上是有改善的。傾銷後達成效率之廠商數雖較傾銷前減少，然而，就各項效率之改善度來看，傾銷後的這段期間確實大為提高。 影響水泥業經營效率的因素很多，而傾銷復之利得亦僅為原因之一，然本研究針對傾銷前後的財報數據以DEA進行分析之結果與水泥工會歷年的水泥銷售量作比較，發覺傾銷前後生產力的改善進步與生產數量有正向關係，因此，我國對國外傾銷的業者課以反傾銷稅，確實對我國水泥產業有正向的利益與成長。

Traditional industries, whose competitiveness and sustainability has encountered great challenges after Taiwan joined WTO, is facing tremendous pressure from market opening and free competition. In this regard, we chose 8 firms from Taiwan's cement industry that closely linked with people's livelihood to be the research objective. As cement industry has experienced the anti-dumping wave of the world and relevant lawsuit has been settled in Taiwan, this study evaluates the operational efficiency during the dumping period (from 1998 to 2005). In this paper, we utilize Data Envelopment Analysis (DEA) and Malmquist Productivity Index to analyze and detect the change of relative efficiency for both individual firms and cement industry as a whole, before and after anti-dumping duty was imposed during the aforementioned period. With respect to TFP and TEC indexes of the cement industry, the low total factor productivity (TFP) of the industry is caused by inefficiency in technology and production. According to the result from concrete diagnosis, we conclude that both TFP and TEC of the cement industry have significantly improved after anti-dumping duty was imposed. Although the technology used in cement industry is inefficient, both TFP and TEC are not affected. For EC index, technical efficiency of the cement industry declined due to technological inefficiency before dumping took place and deterioration in economy of scale after dumping occurred, which were resulted from the change in enterprise structure. Before dumping occurred, nearly 1/3 of the firms were operating efficiently, with 5 firms being inefficient. The avenge efficiency ratio of the 5 firms is 99.1%, indicating that 0.9% of the resource was wasted in economic terms. After dumping occurred, 6 inefficient firms were found, with average efficiency ratio slightly rose to 99.13%. Therefore, although the number of inefficient firms increased after dumping took place, the use of resources improved. The operational efficiency of cement industry can be affected by various factors, one of them being the gains from imposing anti-dumping duty. In this research, financial figures from the ment industry before and after dumping occurred were analyzed with DEA method to be compared with historical figures, and we conclude that improvements in productivity were positively correlated with the amounts of production. In summary, imposing anti-dumping duties to foreign dumping firms was in the interest of domestic cement industry.