This paper presents the results of study on ,60,Co ,γ,-ray induced chromosome aberration in rabbits peripheral blood lymphocytes irradiated in partial and whole body and the aberration rate decrease with the time of post -exposure. The experiments included 5 groups, it was whole — body exposure group,partial— body exposure (abdomen and pelvic cavity) group,blood irradiation group in vitro and control group respectively. Radiation dose was 3.0Gy delivered at rate of 0.5Gy/min. The results show that it was no significant diffrences between whole body and in blood irradiation group. The chromosome aberration yield in whole body exposuregroup was higher than that in partial — body group and in the abdomen exposure group was higher than in that in the pelvic cavity irradiation; The chromosome aberration rate decreased with the time of post -exposure in partialand whole body by γ-ray irradiation.