Total ionizing dose （TID） effects of the deep submicron MOSFET （metal oxide semiconductor field effect transistor） with delta doping profiles and uniform doping profiles in the channel region are analyzed in this paper. The influence of both doping profiles on the leakage current and threshold voltage is investigated. The results show that, the leakage current of MOSFET with delta doping profile is 2—3 orders lower than that with the uniform doping profile when the radiation dose is lower than 500 krad. Yet when the radiation dose is higher than 500 krad, the delta doping profile dose not show significant improvement compared with uniform doping profile as the trapped holes in the MOSFET saturate. But the threshold voltage shift is about 40 mV less than that with the uniform doping profile. Therefore, the TID effects of the deep submicron MOSFET can be improved by adopting the delta doping profile. The optimization of the delta-doping profile to further improve the TID effects is also given in this paper, which provides the guideline for the radiation hardened design.