The subject of this study is to examine the determinants of the real exchange rate in Taiwan. The sample period is from the first quarter of 1982 to the second quarter of 2011, and the variables include the real exchange rate, terms of trade, productivity differential, the real oil price, reserve differential, real interest rate differential, and the net foreign assets of Taiwan and America. The empirical results show that there is no cointegration between the real exchange rate and independent variables. Using a VAR model, this study finds that although the central bank of Taiwan would intervenes the real exchange rate, the variable related to the economic growth is still significant. At 5% significance level, an increase in the productivity differential leads the real exchange rate to depreciate. In addition, from the result of the granger causality test, this study finds that there exists unidirectional causality from the productivity differential and central bank intervention respectively to the real exchange rate. The effect of central bank intervention on the real exchange rate only persists one period, and the effect of the productivity differential persists two more periods. Therefore, it can be concluded that when estimating the future real exchange rate, it may be useful to take the productivity differential into account.