在選舉結果的詮釋上，地方型態、單一席次的縣市長選舉投票率反映的是公民參與的強度，是民主政治發展過程中的重要觀察指標。本研究的主要目地是檢驗我國縣市長選舉投票率的影響因素，考慮的因素包括空間構面的人口數與青壯年人口比率二項因素、治理構面的高等教育比率、平均每人每年可支配所得與施政滿意度三項因素、以及政治競爭性構面的選前民調接近性與連任二項因素。收集的資料包括2001年、2005年與2009年的三次縣市長選舉的投票率資料、縣市統計資料以及TVBS民調中心資料。迴歸分析的結果發現，對於我國縣市長選舉投票率而言，在5%的顯著水準下，施政滿意度與連任因素並不是顯著的解釋變數；最終以逐步迴歸建立之最佳整體迴歸模式則顯示:選前民調接近性雖是顯著的解釋變數，但是由於解釋能力並不強，最後僅有青壯年人口比率與平均每人每年可支配所得是顯著變數，二者是影響我國縣市長選舉投票率的主要因素。

This paper uses several regression models to examine the impact of spatial factors, governance indicators, and political competitiveness to turnout rate across the 21 county magistrate/city mayor elections in Taiwan. Data of the year 2001,2005 and 2009 are collected. Population and ratio of middle-age population (15-64 years) are considered as spatial factors; ratio of the higher educated, mean disposable income and administrative satisfaction are considered as governance indicators; Closeness of opinion survey before election and re-election are considered as political competitiveness factors. Results show that closeness of opinion survey before election has little positive impact on turnout rate. Turnout rate, however, varies negatively with the ratio of middle-age population (15-64 years) and mean disposable income. These two significant factors may help explain turnout rate of county magistrate/city mayor elections.