This paper attempt s to test the risk premium of Taiwan's U.S. dollar forward exchange market. This study doesn't come to conclusive results about the efficiency of Taiwan's U.S. dollar forward exchange market. While this research finds that the market after reopening becomes more efficient than the market before reopening, and the degree of central bank intervention has been decreasing. The risk premium cannot be explained by their conditional variances. In addition, the empirical results show that the riskless rate is not a good predictor of the risk premium for the forward exchange market. But after taking the stock market into consideration, this paper finds that there exists a relation between the excess return s of the forward exchange market and the stock market. It also finds that the forward exchange market and the stock market doesn't exist a long-term cointegration by using single latent variable model.