This paper deals with the observation of micronuclear incidence in PCE bone marrow of Wistar rats. Two groups of rats were fed irradiated foods for 110 days and 150 days respectively. One was fed irradiated foods, in which irradiated foods occupied 80% of total food. Another was that in which irradiated vegetables being added in 3%. The radiation dosage was 2 kCy (200000 rads) .,In addition, there were negative control rats fed general foods and positive rats treated by cyclophosphamide or whole body irradiation with 2 Gy (200 rads) . In this experiment, Giemsa staining, Harris hemotoxylin restaining and acridine orange fluorescence staining were used. From the results, it was indicated that the incidence of PCE with micronuclei in bone marrow of rats was not increased in the animals feeding mixed irradiated foods or in irradiated vegetables.