Abstract: Maize is a major crop in northeastern China, and its production plays an important role in animal husbandry of China. In this paper, a 30-year long-term corn field experiment was investigated to study the effect of fertilization and straw return on chemical and physical properties and the diversity indices of arbuscular mycorrhizal fungi(AMF) and bacteria in maize rhizosphere soil. The results showed that, addition of straw return had effects on soil chemical and physical properties, and significantly improved organic matter content in particular. Compared with chemical fertilization, treatment with addition of straw return significantly increased Shannon index and abundance of AMF and bacteria. P fertilization plus straw return, increased Shannon index and abundance of bacteria by 27.9% and 63.6%, and those of AMF increased by 35.7% and 40.1%, respectively. Soil chemical and physical properties were closely correlated to Shannon index and abundance of AMF as well as bacteria, and organic matter content and available nitrogen were significantly correlated with Shannon index and abundance of AMF and bacteria in a range 0.7~0.9 at 0.05 level, respectively.