Abstract: Researches have already shown that aging of strains is common in the growth process of mushroom, and may accompany with a series of changes in physiology and biochemistry.This paper reported the invesitgations on the aging of the five strains, and results showed that changes in the relative rate of elecrical conductivity, MDA content, and the activities of SOD and CAT for each went differently.However, a decrease trend activity of ACP wasobserved and the activity of ACP was significantly different when each spawn was treated with different times of cultivating, which could be used as an indicator of aging degree of Agaricus spawn strains aging of mushroom.