Abstract: Objective To observe the effect of lighting asymmetry on the blood physiological and biochemical indexes of normal SD rats. Mothods Eighty SD rats, weighting 60～80 g，were kept on the rack with different layer (A,B,C,D) after one-week's adaption . Light-intensity and light area were measucrd in each cage. Food consumption and body weight were calculated every 2 weeks. Blood physiological and biochemical indexes were detected after 8 weeks. Results (l)The light-intensity among inner inside of four layer's cages was no significant difference (P＞0.05)，however, there is a significant difference light-intensity and cage-area in outside and median site of cages in each layer (P＜0.01, P＜0.05).(2)The food consumption and weights of A and D layers rats have no obvious differences (P＞0.05).(3)The blood physiology shows WBC,MCHC, HDW, MPV, NEUT, EOS, BASO and Retic of female rats from A to D layers varied at different degrees (P＜0.05,P＜0.01). (4) The Blood Biochemistry shows AST, TBIL, UA, TG，CK, and CK-MB of female rats from A to D have obviously decreased, ALP and GLU have significantly increased (P ＜0.05，P＜0.01); while TBIL and CK-MB of male rats were markedly decreased, GLU and BUN were notably enhanced (P＜0.05, P＜0.01). (5) Female rats compared with the males on the same layer, some physiological and biochemical indicators of blood there were significant differences(P ＜0.05, P ＜0.01). Conclusion The light asymmetry was in different layer of the cages can cause the change of blood biochemical indexes to a certain extent, and the change was more obvious in female rats.

Key words: Lighting asymmetry, SD rat, Blood physiological and biochemistry