Purpose: The purpose of the study was to identify the effects for 4-weeks muscle strengthening exercise program on pain, fatigue, and physical function(muscle strength of leg, walking competence, balance, flexibility of patella) in elderly women with total knee arthroplasty(TKA). Method: Utilizing a quasi-experimental design, 30 TKA patients consisted of the experimental group (n=15) and control group (n=15). The experimental group participated in the muscle strengthening exercise program, twice a day for 4 weeks. Data were analyzed with SPSS WIN 18.0 program, using repeated measure ANOVA. Result: As time goes by, There were significant differences in muscle strength of leg (F=6.60, p<.001), walking competence(F=7.15, p<.001), and balance(F=17.55, p<.001) between the experimental and the control groups. Conclusion: The findings of this study revealed the positive effects of muscle strengthening exercise program in elderly women with TKA.