Abstract: Homemade bipolar process components to be applied in spacecraft have the risk of enhancing the low dose rate sensitivity. Therefore, the low dose rate radiation test evaluation is essential for newly-applied bipolar process devices. In this paper, the irradiation tests with low dose rate of 0.01 rad(Si)/s are carried out on some homemade bipolar devices. The sensitivities of different process devices under different bias conditions are analyzed. Their radiation hardness ability against the low dose rate radiation is analyzed as compared with the results obtained from the 0.1 rad(Si)/s test. A method for evaluating the radiation damage enhancement factor and the parameter selection criterion are proposed. The sensitivity enhancement of various types of devices under the low dose rate irradiation is discussed. The total dose radiation hardness ability of each device is given in the end.