Taiwan is a typical small, open economy with a highly degree of free capital flow. Among the key market fundamentals of market for foreign-currency exchange, it is not enough to reflect the accuracy of exchange rate by just reviewing the factors on the monetary and trade approach. It could be much helpful to improve the accuracy of exchange rate forecasting if uncertain impact from the financial market such as individual’s expectation behavior could be included. In addition, Taiwan is a so-called “Island-Economy”. In order to slow down the impact of rapidly fluctuations of exchange rate on the import and export. Central Bank of Taiwan used to have an active policy to stabilize the market for foreign-currency exchange, so that there might be difference between actual exchange rate and equilibrium exchange rate. While the effects of several general variables such as money supply, interest rate, balance of payments and wholesale price index etc.. On the fluctuations of the exchange rate have been well documented, less is known about the effects of individual expectation behavior onto the determination of exchange rate. One reason for this limited knowledge has been the lack of a measurement technique for quantifying this variable. In this report, we try to quantify this variable and adopt MARIMA transfer function model for an empirical research. It would be helpful to lengthen the shortness of exchange rat forecasting efficiency by using monetary structural model and random walk model. I am convinced that this particular portion of the paper could be thought of as seeking to expand the analytical inadequacy in prior related researches and make a contribution to new insights.