本文以民國七十二年、七十五年之立委選舉為對象，以臺灣地區之三三○個鄉鎮市區為研究單位，著眼於一個地區的社經發展程度，黨外後援會（或民進黨）的提名策略、失業率、新生代選民壓力，以及省籍結構等對於政黨競爭之影響加以探討。研究結果發現上述因素對政黨競爭皆有影響，其中尤以提名策略及社經發展程度對政黨競爭的影響最為突出，在目前臺灣地區面臨社經、政治轉型的今天，尤其值得注意。 This study examined the determinants of party competition in Taiwan. Since Taiwan's socioeconomic development is closely related to the growth of the opposition in the last 20 years, the major hypothesis was that areas with higher levels of development will foster stronger opposition power and eventually more intense political competition. This hypothesis was tested with Taiwan's 1983 and 1986 areal-unit data by controlling for the TCSA (1983) and the DPP (1986) nomination strategy, the local economic conditions (unemployment rate), the age structure (percent of young voters), and the provincial composition (percent of Hakka and Mainder, respectively) in the regression analysis.The results indicate that all factors in the regression model reveal expected results and have statistically significant effects on party competition except for the percent of Hakka variable in the 1986 model. Above all, the socioeconomic development and the party's strategy have the most important influence. Since Taiwan has been facing the transitional stages in economy,society and politics, it's worthy of paying attation to this finding.