Abstract: AM fungi colonization and spore density were investigated in the Rhizospere of Pueraria lobata at Shaanxi Wugong from 2004 to 2005, studied the AM fungi Seasonal characteristic changes. The results shows: AM fungi colonization is different in the different Pueraria and changes by the lobata’s grow. The versicular colonization and total colonization of Fenge maximal occurred in March 2005, the minimal value occurred in April 2005, but the Yaoge’s maximal occurred in Jan 2005, the minimal occurred in Jun 2005. Hypha and arbuscular colonization have same orders in the two breeds, fastigium occurred in summer and low occurred in late spring and early summer, spore peak produced in summer in the Rhizospere of Puerraria lobata. Spore density had positive correlation with abuscular colonization, the minimum value appears in the winter, and the maximum appears in the summer; consist with the growth prosperous of lobata.