Abstract: Objective : To investigate the molecular mechanism of cell death after radiotherapy or radiochemotherapyfor advanced uterine cervix cancer (UCC) and to discuss the apoptosis and expression of Fas protein. Methods : A total of 60 patients with UCC were randomly divided into two groups: the radiotherapy (RT) group with30 patients who received simple external irradiation of the pelvic cavity and after-loading therapy, and the synchronal radiochemotherapy (CRT) group with 30 patients who received one cycle of chemotherapy besidesRT. Biopsy of the UCC was conducted before and during the treatment (group RT: after 10 Gy radiotherapy;group CRT: 10 Gy radiotherapy + chemotherapy for one cycle). The samples obtained in the treatment weredetected to determine apoptosis and the expression of Fas protein using TUNEL and immunohistochemistry. Results : The complete response rate was 50% in the RT group and 90% in the CRT group, respectively (P=0.0012). Before and during the treatment, the positive rates of apoptosis were increased, ranging from33.33% to 66.67% (P=0.02) in the RT group and from 36.67% to 93.33% (P=0.000) in the CRT group, respectively. There was a significant difference between the two groups, especially during the treatment (P=0.02).The positive rate of Fas protein was 33.33% before treatment and 70% after treatment in the RT group. In theCRT group, the positive rate of Fas protein was 26.67% before treatment and 76.67% after treatment. However, there was no change in the expression of Fas in both groups (P>0.05). There was a significant correlationbetween the expression of Fas and apoptosis after treatment in both groups (P=0.015, r=0.755 vs P=0.027, r=0.423). Conclusion : For UCC, CRT can achieve a better remission rate than RT. An additive or synergistic an-ti-cancer effect may be the mechanism of CRT, which is reflected by up-regulating Fas pathway for inductionof tumor cell apoptosis.