本文研究台股之最適反向操作策略，與過去研究不同的，在於使用個股觀點，且使用價格水準決定輸家及贏家。實證結果顯示，當個股價格低於52週高點的一半，且本益比低於10時買入，並在上漲5~10%左右或下跌75%以上或持有2或3年時賣出，可創造最高報酬。研究結果並顯示，在台股採用此策略，以電子股和傳產股最適合。 / This paper tries to construct the best contrarian strategy which means that past losers will outperform past winners for Taiwan stock market. Instead of following previous papers to use past returns and be portfolio-oriented, “price” and “individual stock” are the main factors in the strategy. Initially, the most adequate timing for buying stocks was determined. Then the feasible selling policy was formed. After the optimal contrarian strategy was constructed, industrial factors were investigated. The results suggest buying stocks with P/E ratio under 10 when their prices are lower than their half of the previous 52-week high, and selling them when prices drop about 75% or rise about 5% or 2 or 3 years later since buying them, depending on which one appears earlier. Finally, the findings also show that electronic stocks are most applicable to the contrarian strategy.