Isthmus Blood Flow (IBF) was measured on 3 conditions in the present study; normal, inject-ing HCG and EA by hydrogen gas clearence method. The results were as follows: 1) IBF (ml/100g/min) in laying-hen was significantly higher as compared with that in prelaying-hen (p<0. 05). 2) IBF in laying-hen was higher significantly by injecting HCG than before injection(p<0.05); but this increase was not found in the prelaying-hen. 3) EA on Yigen enhanced IBFsignificantly (p<0. 05).