本研究運用相對評價法中之PBV(Price to Book Ratio)乘數，進行橫斷面 迴歸分析，判斷股價低估(undervalue)或高估(overvalue)，並利用判斷結果進行投資組合部位建立。選取樣本利用台灣50 指數成分股排除公司規模之影響，而研究結果顯示，利用PBV 低估的股票進行多部位建立，在研究期間 全期中，可以明顯超越市場報酬，但在空部位建立則無法超越市場報酬。 研究中並發現，極端值對績效造成影響，其因素為金控及銀行類股與景氣 循環股產業特性所致。 / This research applied the multiple of the price to book value in the relative valuation to begin cross-section regression analysis and to evaluate if the stock price was overpriced or underpriced. The result can be used to develop the investment portfolios. This research used the constituents in Taiwan 50 Index as samples in order to avoid the size effect. During the whole period, we found that we could gain excess profit obviously and defeat the market return by utilizing those stocks underpriced in PBV to develop the long position. However, we could not defeat the market return by developing the short position. In the research, we also found that the extreme value could affect the investment return, which result mainly from both stocks of financial holding companies and banks and stocks of business cycle industries.