Abstract: The impact of the total ionizing dose(TID) on the endurance and the data retention characteristics of the typical floating gate Flash is investigated experimentally by the TID test, the program/erase cycling, the data retention test, and their combinations. A relatively high total dose of 150 krad(Si), and various bias conditions including the dynamic bias, are introduced and evaluated. It is demonstrated that the impact of the TID on the endurance is nearly negligible. And the impact of the TID on the data retention is majorly reflected in the radiation-induced leakage current (RILC), and the impact can be ignored as long as the data is refreshed after the TID test. For the system-level applications, an increased number of data refreshings is suggested, to reduce the impact of the RILC on the data retention.