Objective To study the effect of Huojing Oral Liquid（oral liquid for activating sperms） on ultrastructure of sperm tail in idiopathic asthenospermia and to explore its mechanism.Methods Totally 146 cases with idiopathic asthenospermia were divided into 3 groups according to a level sperm viability

i.e.15% ≤A group <25%

5% ≤B group< 15%

C group< 5%.All the groups were treated with Huojing oral liquid

50ml

twice a day

4 months as one course of treatment for totally two courses.The seminal fluid analysis and observation with electronic microscope before and after treatment were done for 3 groups.Results After treatment

there was a more significant improvement in mitochondria pathological changes than in dense fiber and axoneme pathological changes.Array disorder of mitochondria was the most significant improvement and in group A the improvement of mitochondria deficiency was the best.The improvement was the best on array disorder of dense fiber and axoneme.There showed a significant improvement in A level sperm viability of each group after treatment（P<0.05 or P<0.01）.Conclusion Huojing Oral Liquid can improve significantly the ultrastructure of sperm tail in idiopathic asthenospermia.More significant improvement is in mitochondria pathological changes.