This research use the box spreads strategy to examine the efficiency and arbitrage opportunities of Taiwan Weighted Stock Index Option (TXO) market during the period of 2007. From the empirical evidences, we find transaction costs seem critical factors influencing the appearance of arbitrage opportunities. In addition, we discuss the profit of arbitrage opportunities and other possible factors that will influence the arbitrage opportunities, such as the size of the spread, distance from the due date, the occurrence of time and the occurrence of months. The results indicate: 1. Most of arbitrage opportunities appear when the difference of two strikes is small. 2. Most of arbitrage opportunities appear in contracts with shorter time to maturity, but the higher profits appears in ones with longer time to maturity. 3. Most of arbitrage opportunities occurs at the market opening. 4. Most of arbitrage opportunities occurs at the second half of year.