Abstract: Objective: To investigate the molecular mechanism of cell death after radiotherapy or radiochemotherapy of locally advanced uterine cervix cancer (UCC) and to discuss the apoptosis and expression of Bax and Bcl-2 protein. Methods: Forty-nine patients with UCC were randomized into two groups: the radiotherapy (RT) group with 25 patients who were given simple external irradiation of the pelvic cavity and after-loading therapy and, the synchronal radiochemotherapy (CRT) group with 24 patients who were given 3 cycles of chemotherapy (DDP+5-FU) besides the RT. Biopsy of the UCC was conducted before and during the treatment (group RT: after 10 Gy radiotherapy; group CRT: 10 Gy radiotherapy+DDP+5-FU×1 cycle). The samples obtained in the treatment were employed to determine apoptosis and the expression of Bax and Bcl-2 protein using TUNEL and immunohistochemical methods. Results: A complete response achieved 52% of the RT group and 79.2%ofCRT group, respectively (P=0.044). Before and during the treatment, the positive rates of apoptosis were increased, ranging from 24%to 60%(P=0.01) in the RT group and from 20.8% to 87.5% (P=0.000) in the CRT group, respectively. There was a significant difference between the two groups, especially during the treatment (P=0.03). The positive rate of Bax protein was increased, too. They were 24% and 25%, before treatment, and 52% and 79.2%, after treatment, in the RT and CRT group, respectively, with a significant difference(P=0.021 and P=0.000). There was a significant correlation between the expression of Bax and apoptosis, after treatment in both groups (P=0.015,r=0.827 vs P=0.027,r=0.523). However, there was no change in the expression of Bcl-2 in the two groups (P>0.05). Conclusions: There is a better remission rate in CRT of the UCC compared to the RT. An additive or synergistic anti-cancer effect might be the mechanismofCRT, which is realized byup-regulatingBaxpathwayfor induction oftumor-cell apoptosis.