Objective: To explore therapeutic effects and its mechanism of Liuwei Dihuang pill in deferring senile. Methods: Two hundred and ninety-two patients with kidney deficiency syndrome were divided into two groups: treatment group (242 patients) and control group (50 patients). The Liuwei Dihuang pill was orally administrated to patients in treatment, and placebo to control group. At the same time, experimental study was conducted. Results: The senile symptom score of kidney deficiency syndrome in treatment group decreased after treatment compared to that of before treatment (P<0.001,0.01), while in control group there had no significant difference before and after treatment. The scores of near vision, grip strength, psychic senile and instant memory improved obviously after Liuwei Dihuang pill treatment (P< 0.01), but the scores in control group had no significant changes. In treatment group, the contents of serum peroxide lipid, adrenocortical hormone, super-oxide dismutase, plasmic testosterone, estradiol and cellular immune function had significant improvement after treatment compared to those of before treatment(P<0.01), while in control group there had no significant changes. Pathological experiment showed that Liuwei Dihuang pill had such effects as nourishing liver and kidney, decreasing blood pressure, blood sugar and blood-lipid, anti-arrhythmia, anti-arteriosclerosis, and anti-stress. Conclusion: The Liuwei Dihuang pill is effective to anti-senile, which also has pathological basics.