Abstract: Objective: To study the outcome of locally advanced or recurrent rectal cancer treated by three dimensional-conformal radiation therapy (3D-CRT) and the change of multi-tumor makers protein. Methods: 60 patients with locally advanced or recurrent rectal cancer were irradiated by ex-ternal beam radiotherapy to a total dose of 40 Gy,then 60 patients were divided randomly into twogroups: 30 cases received 3D-CRT (3D-CRT group), 30 cases received conventional radiotherapy(con-trol group). Multi-tumor makers protein of the 3D-CRT group was assessed before and after radiation therapy and after the second recurrence. Results: The overall response rates were 86.7% and 70% inthe 3D-CRT group and control group,with the difference insignificant (P>0.05). Yet, for the 3D-CRTgroup and control group,the overall 1-, 2-, 3- year survival rates were 80%, 53.3%, 36.7%; 56.7%,40%, 13.3%, P=0.021 3. The contents of CEA 、 CA19- 9 、 CA242 、 FER of the 3D-CRT group after ra-diation therapy comparing with before radiation therapy decreased significant, the difference is signifi-cant (P<0.01).Then the contents increased after the second recurrence,the the difference of the changeis significant (P<0.01). Conclusion: Conventional radiotherapy plus three dimensional-conformal radia-tion therapy may significantly improve the effect of the treatment in locally advanced or recurrent rectalcancer. The multi- tumor makers protein diagnose system is an predictive factors of therapeutic effect and prognosis.