In order to explore the effects of insect hormones on the alkaline phosphatase(ALP) activity and its gene expression level in Bombyx mori,using the 3rd day of the fifth instar silkworm(Dazao) as test materials,the ALP gene expression level and enzyme activity were detected in the hemolymph and the midgut at different time after injecting 20E and JH.The results showed that the ALP expression level was significantly up-regulated at 6 h,12 h and 24 h after 20E or JH treatment in the hemolymph of Bombyx mori,but it was up-regulated only at 12 h and 24 h in the midgut. In the 20E treatment group,the ALP relative expression level was the highest at 6 h in the hemolymph,which was 2.3 times of the control group;but it was the highest at 12 h in the midgut,which was 2.8 times of the control group.After JH treatment,the ALP expression level in the hemolymph and midgut were the highest at 24 h,which were 3.7 times and 4.7 times of the control group respectively. In addition,the ALP enzyme activities were significantly activated in the hemolymph and midgut by 20E and JH.The hemolymph ALP enzyme activity was significantly higher than the control group at 6 h,12 h and 24 h after 20E treatment,and the highest activity at 12 h was 33.34 U/mg;While the activity of ALP in the midgut were significantly higher than the control group only at 12 h and 24 h,their activities were 37.68 U/mg and 40.95 U/mg respectively.Meanwhile,the ALP activity were also significantly higher in the hemolymph and midgut at 6 h,12 h and 24 h after JH treatment,among them,the ALP activity in the hemolymph had the highest value of 42.29 U/mg at 6 h,while the enzyme activity was rosed to the highest value of 46. 84 U/mg at 12 h in the midgut.The above results indicated that the ALP expression level was regulated by 20E and JH in Bombyx mori,and the effects of hormones on the gene expression level were consistent with the change rule of enzyme activity.