  Magetoresistive Random Access Memory (MRAM) was irradiated by 60Co
{\gamma}-rays and electron beam. The test of synergistic effect was performed
under additional magnetic field when irradiation. We analyzed Total Ionizing
Dose (TID) and synergistic damage mechanism of MRAM. DC, AC and function
parameters of the memory were tested in radiation and annealing by Very Large
Scale Integrated circuit (VLSI) test system. The radiation sensitive parameters
were obtained through analyzing the data. Because magnetic field imposed on
MRAM when the test of synergistic effect, Shallow Trench Isolation (STI)
leakage or Frenkel-Poole emission of synergistic effect was smaller than that
of TID, and radiation damage of synergistic effect was lower than that of TID.
