Roots and rhizosphere soil samples were collected at jointing stage and harvest stage, and the colonizationand sporulation of Arbuscular mycorrhizal（AM） fungus were detemined by the way of wet sieve-sucrose centrifuga-tion and staining microscopy. Results showed that at jointing stage sporulation in chemical fertilizer treatment wasmore than that of AM fungal treatment. In all treatments, the number of spores turned to decline from jointing stageto harvest, while the infection rate increased. At jointing stage, spore number was greater than at the harvest, and theinfection rate was on the contrary. It was obvious that two kinds of fertilizers both increased spore infection rate, butthe exogenous chitin fertilizer was obviously higher, which was 13.91 times of chemical fertilizer treatment. Sporesdecrement rate was positively correlated to mycorrhizal infection rate. It was suggested that the different fertilizershave a certain influence and regularity on colonization and sporulation of Arbuscular mycorrhizal fungus, especiallychitin fertilizer can create a better optimum condition. The study would provide a theoretical basis for later explora-tion.