教育成就的性別差異雖已逐漸消失,但平等化的歷程與型態,仍未有太多的討論與研究。尤其,門檻假說所預期的「開發中國家女性教育的不利改善歷程,將呈現非直線性的演進」,更缺乏實證證據。本研究分析了過去五十年的台灣,男女在高中與大專階段教育的平等化歷程以驗證門檻假說,並說明經濟發展與教育擴張對於性別間教育均等化的影響。本研究整合1990年~2001年各期台灣社會變遷資料,獲得超過四萬筆的樣本,劃分九個出生群組,以估計教育成就性別差異長時期演變情形。結果顯示,女性在高中階段與大專教育上的相對不利情形,會因經濟的發展而獲得改善,但在不同的經濟發展與教育擴張程度下,性別差異的改善情形並不相同,各階層因經濟發展而提高教育成就者,仍是男先女後,其順序分別為上階層男性、上階層男性與部分上階層女性、上階層女性與部分下階層男性、下階層男性與部分下階層女性,最後是下階層女性。這種順序造成了演變過程非直線的走勢,符合門檻假說對開發中國家社會演進過程所預期的趨勢。 Although gender inequality in education has diminished these years, its pattern and process has not received much attention. The Threshold Hypothesis has generated a few discussions and controversy. However, systematic empirical evidence to evaluate this hypothesis has been less forthcoming. The purpose of this study, therefore, is to demonstrate the equalization pattern and process of gender inequality in education for the last forty years in Taiwan, and to explain how the key factors involved are affected by economical development and educational expansion. We reorganize the 1990-2001 “Taiwan Social Change Survey” data by birth cohorts, and estimate the gender effect on the opportunity of receiving mid- and higher education from 1951-1991. The results show that the equalization process is not linear, but rather ladder-like, and is consistent with the assumption of Threshold Hypothesis. Further, the equalization of gender inequality in education differs by socio-economic backgrounds: The order of catching up with the educational attainment of upper level male is upper level female, lower level male, and lower level female, respectively.