Broadbean, as a widely planted legume in the southern part of China, contains abundant provein and is often grown as a forage crop or a green manure crop, but, the yield of broadbean is very low on the purplish soils of Sichuan Province, especially on grey-brown purplish soil. In the recent years the effects of VA mycorrhiza on trace element absorption by plants have been emphasized. But so far there has been few report on the effect of VA mycorrhiza on Mo and P absorption of broadbean grown on purplish soils. The biological effect on nutrient absorption of VA mycorrhiza was studied to find the way of using VA mycorrhiza in purplish soils. Research results showed that VA mycorrhiza could promote Mo and P absorption of broadbean plant. Ground phasphate rock was difficult to be directly uptaken by plants, but it could be utilized when plant was inoculated with VA mycorrhiza. VA mycorrhiza also could promote the grouth of host plants. The roots of the plants inoculated with VA mycrrhiza developed better, especially when Mo, P and VA mycorrhiza were used together. Result show that the nodules on plant treated with Mo+P+VA mycorrhiza were bigger in size and the greatest in quantity and those treated with Mo+VA mycorrhiza carne the second. Meanwhile, the resistance of broadbean plants treated with Mo+P+VA myeorrhiza or Mo+VA myeorrhiza to Botrytis fabae sardina and senility was enhanced.