Two groups of rabbits stressed by elevated tempera ture, length of photoperoid and relative humidity were injected by F.S.H. and L.H. in one group and these two hormones in combination with glucocorticoid in the other group. In both groups the diameter was corrected to normal. The damage and decrease in the Sertoli cell number was not corrected, also the sper matogonial damage. The number and Sertoli ratio of spermatocytes were not corrected by F.S.H. and L.H. But it was corrected by the group of the three hor monal association. In both groups the Sertoli cell ratio and total number of spermatids were corrected. The qualitative pathogenesis of hormonal action for the F.S.H., L.H. group was blokage of migration of spematids, elongation and maturation of spermatids in situe and disturbance of cytokinesis. Peculiar to the seconed group of the three hormonal association was, one generation of spermatocyte or one generation of spermatid through out the whole cyclic stages.