由於共同基金之操作績效關係投資人之財富，因此本研究擬探討國內開放型股票型共同基金之投資效率，並進一步找出可能影響基金績效的因素。 本研究期間為民國91至93年共計三年資料，共有126支開放型股票型共同基金符合成立已滿三年以上條件，並採用資料包格分析法，選取投入項為年化標準差、累計買進週轉率和各項費率，產出現則為淨值報酬率，以估計共同基金的各項效率值。 本文之結果顯示：91年至93年總效率值不佳主要是由於基金經理人操作績效不佳之純技術效率部分表現不良。共同基金之績效與基金的規模大小有顯著正向關餘，而與週轉率高低有顯著負向關餘，以及不同投信公司之基金效率亦有顯著差異。此外，投資不同股票類型的基金其績效亦不同。本文亦發現資料包絡分析法之效率值與夏普指標、詹森指標和崔納指標等三項傳統績效衡量指標有顯著正相關，顯示資料包絡分析法適用於基金績效的衡量。

Since the portfolio performance of mutual funds is influential to investors' wealth, it becomes an important area of research. The popular indices of performance evaluation, Sharpe index, Treynor index and Jensen 's alpha, have a number of shortcomings reported in the literature. This study tries to use a non-parametric approach, Data Envelopment Analysis (DEA), to evaluate the performance of the open-end common stock mutual funds in Taiwan and further to examine the effect of influential factors on efficiency. The research period of this study extends from 2002 to 2004 and this study consists of 126 samples. The research results reveal that the poor performance of mutual funds is due to low pure technical efficiency, not scale efficiency. Moreover, the efficiency measures from DEA are positively related to three traditional performance indices. The regression analysis further examines the relationship between efficiency measures and influential factors and finds that mutual funds performance is positively related to asset size but negatively related to turnover.