Abstract: The results of sampling investigation at 7 sites in three provinces of south China showed that all of the seven root samples of Teak were infected by Arbuscular mycorrhizal fungi with an infecting rate of 40% 70% and infecting index of 11.67 19.17 in the natural condition. The research results of teak seedlings of 12 provenances inoculated artificially by 4 AMF showed all the inoculated treatments were with an infection rate of 70% 100%. 4 clones of teak seedlings were inoculated with 3 AMF and the infection rate was 86% 100% and the infection index 28.33 52.5. The height, ground diameter and biomass of inoculated seedlings increased respectively by 54.0% 408%,5% 430% and 116.4% 2-574.8% compared with the control seedlings. The results of variance analysis showed that the differences among clones, mycorrhizal strains or clone×mycorrhizal strains on seedling height, ground diameter and biomass comparing with contrast were high remarkable. In conclusion, the three mycorrhizas strains have inoculation effect on the growth of seedlings, with the best one strain G9004, followed by strain G6008 and strain G3006.