Technical trading rules for TAIEX futures are studied in this research. They are parameterized and composed of several conventional technical indicators of TAIEX. To find the optimal parameters of the rules, genetic algorithms are used for specific learning objectives. Ten experiment cases in a decade that including swing upward, swing downward, and uncertainty cases are designed to compare the performance of the winning-percentage-oriented or the profit-oriented optimal trading rules. The results show that the winning-percentage-oriented optimal trading rules are superior. Their winning percentage performance is better in most cases and the profit performance is better in more than half of cases, especially, the total profit performance in the 10 cases. Keywords: Trading Rules, Genetic Algorithms, Winning-percentage, Technical Indicators, TAIEX Futures