Linear response theory was used to predict threshold-voltage shifts for CC4007-NMOS device at dose rates of 0.1, 2.3, 44 and 91rad(Si)/s. These predictions were compared with the threshold-voltage shifts obtained after 60Co irradiations actually performed at these dose rates, and the agreement is excellent. Also, we use the linear response theory to predict the response of CC4007-NMOS device during radiation and 25℃ annealling for high and low-dose-rates. According to the predictions, under the same conditions of radiation and annealling, the threshold-voltage shifts caused by high dose-rate irradiation after room temperature annealling were equal to that by low-dose-rate irradiation within the limit of error, but the total times for both were the same. Finally, the failure doses for CC4007-NMOS device at different dose rates of irradiation were predicted also using the linear response theory.