After considering the selectivity of labor force participation, this study estimates Taiwan's wage equation based on quantile regression, and examines the relationship between gender wage discrimination and wage distribution by decomposing the male and female wage differential. The empirical results show that evident heterogeneity exists not only in labor supply selectivity but also in rates of return of worker's characteristics across the conditional distribution of wages. In consequence, gender wage discrimination changes with wage level, while low skilled female workers suffer the most. Relying on the results of quantile regression, this study provides new empirical evidence on Taiwan's wage equation and gender wage discrimination that are different from those presented in the existing literature.