Abstract: Arbuscular mycorrhiza （AM） was innoculated to the host plant （sorghum） and grown in three compartment pot culture system. With addition of different supply levels of nitrogen and phosphorus fertilizer into the mycelium compartment， the aim of this paper was to investigate the effect of arbuscular mycorrhiza on sorghum growth and nutrition absorption ability. The results showed that the arbuscular mycorrhiza colonization rate reached 70%; the innoculation increased the dry matter and chlorophyll content， and significantly increased the total nitrogen and phosphorus contents of sorghum. In the innoculation of sorghum， the nitrogen content was increased significantly with the increasing N levels， while decreased with the increasing P levels. When in the treatment of 4 mmol·L-1 nitrogen and 001 mmol·L-1 phosphorus （N2P1）， the plant total nitrogen content was the highest. The phosphorus content was increased with the increasing N and P levels， when in the treatment of 4 mmol·L-1 nitrogen and 0。1 mmol·L-1 phosphorus （N2P2）， the plant total phosphorus content was the highest. Wherefore the nutrition absorption of AM fungi was affected by the interaction of nitrogen and phosphorus.

Key words: arbuscular mycorrhiza fungus, fertilizer, nitrogen, phosphorus