A kind of purposes of the alcohol extracting thing of longan seed in the drug of preparation treatment nephridial tissue hypofunction. The alcohol extracting thing of the longan seed includes ethanol crude extract, and the ethyl acetate portion successively obtained with ethyl acetate, extracting n-butyl alcohol crude extract, n-butanol fraction and remaining water section. Preferably, the ethyl acetate portion of the alcohol extracting thing of longan seed has the effect for the treatment of nephridial tissue hypofunction.
