Abstract: Arbuscular mycorrhizae have ability to improve mineral quality of fruit tree, replacing the fertilizer, so called the biological fertilizer . Paper analyzes four biological effect of arbuscular mycorrhiza, including promote plant growth, enhance absorption of mineral nutrition, improve water metabolism and resolve the problem of re-inseminator in fruit tree . Mechanisms of four arbuscular mycorrhizal biological effect are explained. , as well as paper brings forward the arbuscular mycorrhizal necessity in fruit tree. Arbuscular mycorrhizal propagating is to study the hot point i n future.