The 2008 Legislative Yuan elections in Taiwan were held under a new electoral system, a combination of single-member districts with a plurality system, the national nonpreferential list proportional representation system, and the single nontransferable vote system for the aboriginal districts. This work develops a forecasting model and hypothesizes that the partisan voting behavior of Taiwan`s citizens largely remains identifiable and durable. There are two methodologies used in this study. The first is the use of three-wave aggregate-level electoral data to estimate the out-comes of the 2008 legislative elections, The second employs ordinary least squares (OLS) estimations to evaluate the effects of previous three-wave electoral results on the 2008 elections. Using the first method, the forecast success rate is more than 80 percent. The findings also reveal that the OLS model performs satisfactorily because two of the three coefficients reach statistical significance, This study concludes by listing three implications of the election: that it was a critical watershed in Taiwan`s politics, that there is a geopolitical gap between the north and south, and that minor political parties were eliminated from Taiwan politics.