Effect Of Dihuang Yinzi decoction on lifespan of fruit fly were studied.A small clony of drosophila melanogaster of american wild type was set up and the medium was supplied with 2% or 4%Dihuang Yinzi(a chinese medicine decoction for tonifying the kidney).The result revealed an increase of both mean and maximum lifespan of the female or the male fly treated with the decoction

as compared with a control group.The survival curves were shifted to right and 95% ralative ratio of death in Dihuang Yinzi treated groups was significantly lower

indicating that Dihuang Yinzi prolong the lifespan by its effect mainly on the geratic period of the oganism.