Background: To explore the carcinogenic effect about the veterans of taking atmospheric nuclear weapons testing troops in Gansu, China. Materials and Methods: During 2005-2014, all the veterans of taking atmospheric nuclear weapons testing troops were required to have a medical examination in Gansu, 3721 veterans were requested to make an occupational health examination. They were exposed the radioactive fallout particles from atmospheric nuclear burst (the total β radioactive substances and the        radio-nuclides: ³H, 90Sr, ¹³7Cs, ²³⁹Pu, ⁹⁹Mo ⁹⁵Zr,⁹⁷Zr,¹³¹I,¹³³I,and ¹³²Te etc.), they were away from testing sites 10-30 Km. Cancer patients were required to provide the in-patient case history and check pathologically report. For part of the veterans, the level of radiation dose was 100-150mSv.  Results: There were 40 primary tumor and 25 malignant tumors, incidence rate was 1075 /10⁵ and 672/10⁵; The cancer incidence of the transportation corps was 1253 /10⁵, average age was 48.08 years, average service life was 6.08 years; The cancer incidence of the engineering corps is 762 /10⁵,average age is 55.56 years, average service life was 5.48 years; The comparison of the cancer incidence was shown that the trend of escalation about the cancer incidence along with the servicing year increase; In order of the cancer incidence: gastric cancer, lung cancer, carcinoma of colon, esophagus cancer, rectum cancer and skin cancer, the incidence rate was remarkably increasing (p<0.01). Conclusion: It was shown that the trend of escalation about the cancer incidence along with the servicing year increase, the first was neoplasms of digestive system; it may be due to the contaminated radioactive materials transferred through the digestive tract, hence leading to in vivo irradiation.