Abstract: With 0.8MeV electron irradiating the passivation film with three different thickness of SiO2 at 4 radiation dosages(1013cm-2~1014 cm-2),the radiation hardness of the passivation film was studied through comparing the photocurrent and dark current of the photodiode.It is found after radiation,the characteristics of the photodiodes degrade to some extent.The photocurrent decreases at short and long wavelength,never decrease at middle wavelength(600nm~800nm).On the other hand,the dark current increases with radiation dosage.When the radiation is 1×1014cm-2,the photocurrent is only 80% of that before radiation and the dark current is 40 times of that before radiation.In addition,for photodiodes passivated with thin SiO2,photocurrent decreases slightly,however dark current increases remarkably.Results show that the radiation effect has a relationship with device structure and technics of the film.