Abstract: The virulence of Meloidogyne incognita, Radopholus similis and Fusarium oxysporum f. sp. cubense race 4 on banana cultivars (Musa AAA) in pot experiments was determined by inoculating in greenhouse. Results showed that single infection and complex infection of three kinds of pathogenic microorganism could inhibit the growth of banana, and the complex infection affected the growth of banana more. The root knot index was higher for single infection than complex infection of M. incognita on banana, the disease index was higher for single infection than complex infection of R. similis on banana. The disease index of fusarium wilt was relatively high for the complex infection of three kinds of pathogenic microorganism.