本文主要在探討確定提撥退休金計劃下，投資決策對所得替代率之影響，以提供員工退休規劃及政府政策擬定之參考。首先，我們建構退休金累積模型及所得替代率模型，其中所得替代率之計算是以含通貨膨脹率因子的年金方式給付退休金。然後，將影響退休金累積模型的精算因子：累積期間的投資報酬率，依據過去的月資料配適出其母體分配，以模擬員工未來退休時，使用年金方式給付退休金的所得替代率。本文進一步，提供員工在不同投資報酬下應相對提撥多少百分比，以達到適當的所得替代率水準的參考標準，以滿足員工未來退休時的生活所需。我們以民國87年「勞工退休金條例草案」及台灣投資市場的實証資料進行研究，本研究結果如右：當僱主提撥6%月薪資時，(一)若員工可選擇投資標的，女性、男性員工所得替代率分均值分別介於48%~70%、52%~75%，而且選擇高度風險基金之所得替代率平均值皆較低度風險基金高出45 %，但為了使所得替代率小於60%的機率低於10%，女性、男性員工選擇高度風險基金需較低度風險基金分別多提撥3 %、2 %。(二)若退休基金由勞委會統籌管理，以過去實証平均報酬率8%，計算女性、男性員工所得替代率分別為50%、54%，但為達到60%所得替代率，女性、男性員工需分別相對提撥2%、1%。(三)比較「員工可選擇投資標的」與「勞委會統籌分配管理」兩種退休基金管理方式，若員工可選擇投資標的亦有最低保証收益，結果發現員工可選擇投資標的之投資績效及所得替代率皆優於勞委會統籌分配管理。 / The thesis investigates the impacts of the employee’s investment decision making on income replacement rate for defined contribution plan. We first construct the pension accumulation model to compute the final retirement benefit under defined contribution plan. Furthermore, the empirical data of the investment returns from mutual fund market and that from Labor Insurance Bureau are utilized to simulate the possible investment returns distribution for employee before retirement. The replacement rate is then calculated by assuming the employee will use his/her final retirement benefit to buy a single premium annuity with inflation index adjustment from the insurance company. Finally, based on simulation results from different scenarios, we suggest a relative employee contribution rate in order for employee to reach his/her objective replacement rate under different risk aversion levels. Our results show: 1. If the employee can make investment decision by investing in the mutual fund market, in average, female employee can have 48~70% replacement rate, while male employee can have 52~75%. We also find the replacement rate for employee selecting the high-risk mutual fund is 45% higher than those for selecting the low-risk mutual fund. 2. If the employee can not make investment decision and Labor Insurance Bureau allocate the pension asset, female employee can have 50% replacement rate, while male employee can have 54%. 3. Comparing the above two alternatives under the assumption that the employee has minimum guarantee return in both case, we find the first option can generate higher replacement rate for employee.