共同基金是未來投資理財約主流!專業法人機構在股市之投資比重日益提高，對國內證券市場生態產生結構性改變。展望未來趨勢，隨著股市發展成熟化、上市上櫃公司遽增與金融市場情勢連動關係複雜化等因素，專業投資理財時代的來臨必將成為事實。「專業、分工理財」投資型態將逐漸取代以往投資人自行下海操作之「自助式理財」型態。故共同基金操作績效正是進行本評鑑研究的最大動機，其中辨認基金經理人操作策略與績效顯現最具代表性的指標--選股能力與擇時能力．乃本研究所欲深入探討的主題。本研究模型之構建乃根據 Lee-Rahman (1990) 所提出之改良評鑑模式，簡言之，該模型的發展歷經早期 Treynor & Mazuy (1966) 的理論雛形，並經過 Jensen 針對評鑑擇時能力方面之改進，然後再經由 Bhattacharya & Pfleiderer (1983) 的進一步修正，產生了較完善的整體架構，最後經由 Lee-Rahman (1990) 針對評鑑過程中評鑑迴歸式之殘餘項異質性問題，作一根本的解決，建構完整的基金選股與市場擇時能力績效之評鑑模式。同時並運用幾個傳統績效評鑑指標 (即 Treynor、 Sharpe 與 Jensen 指標三種)，作為基金整體性績效之輔助研究。 實證結果顯示:(一)在基金整體績效評估方面，得到的結果顯示不論研究期間的長短．基金表現擊敗大盤的比例皆高於五成，約介於 60% 至 70% 左右，而在 Treynor、Sharpe 與 Jensen 指標三種不同評鑑模式分析下，基金績效排名有相當顯著的一致性。(二)在選股與市場擇時能力評鑑( Lee-Rahman 修正模型)方面:1.同時兼具選股與市場擇時能力的基金皆有穩定的一致性;2.大多頭時期基金擇時能力普遍提昇、新投信基金績效表現較優異。(三)整合比較結論方面:1.本研究中不同的評鑑模式所得實證結果十分肯定基金績效的持續性與穩定性;2.基金顯著的擇時能力並非基金整體績效脫穎而出的決定性因素，績效傑出與否幾乎決定於選股功力因素:3.台灣股市投資 Bottom-up 的投資邏輯漸漸取代 Top-down ;4.新投信績效已有凌駕老投信的趨勢。 / Mutual Funds Investment will be very popular! While the professional institutionalist's participation being promoted, domestic stock market environment has beenchanged structurally. In the future, accompanied by several reasons such us the_maturationof stock market, dramatic increasing in listed company numbers and more complex correlation in international financial markets, the age stressing on professional financial adversary will come. "Professional financial investment and adversary" will substitute for"Self-adversary" investment. Therefore, measuring the mutual fund's performance is the mailmotivation of my study', and the insight in selectivity ability and market timing ability will bethe subject for further research. The research model is based on the Lee-Rahman's modified model (1990), that is, the model structure was first built by Treynor & Mazuy (1966), improved by Jensen in Timingability measurement, and then revised by Bhattacharya & Pfleiderer (1983), and throughout structured by solving the "heteroscedasticity" in error terms of regressions finally Therefore, the better integral research model on measuring selectivity ability a timing abilityhas been accomplished. Meanwhile, we also use three traditional performance measure(Treynor, Sharpe & Jensen index) to be the general performance research. Empirical results show that (1)By measuring the general performance of mutual funds, we know that about 60%-70% funds managers beat market at each research period, and there exists consistency of fund's performance ranking among those three measures. (2) By using Lee-Rahman modified model (1990), we got three conclusions. First, for those funds consist of selectivity and timing ability, there exists consistency. In bull market period, timing ability of most funds performed better generally, and new funds had better performance. (3) Integral comparative conclusions have four results. First, no matter what measures being used, empirical results confirm stability and consistency in performance ranking. Second, significant timing ability is not the determinate factor of significant performance, significant selectivity ability plays the determinate role. Third, in Taiwan, bottom-up investment strategy gradually substitutes for top-down investment strategy. Finally, new mutual funds investment co. had outperformed old mutual funds investment institutions.