The effect of Dinh lang root extract (DLRE) and (-)deprenyl on memory function and lifespan was examined in OFA-1 male mice. Treatments of either DLRE, (-)deprenyl or their combination were carried out 3 times a week starting at 12 months of age and following to the end of life. DLRE and (-)deprenyl significantly increased the memory function as well as surviving time of aged mice. The drug-treated animals showed a lower rate of loss of body weight than saline treated ones. It suggested that DLRE and (-)deprenyl did not prolong lifespan of mice by suppressing food intake. The combined treatment of DLRE and (-)deprenyl proved to be the most effective.