The purpose of the study was to find fungal isolates expressing potential ability to parasitize the eggs of the nematode Meloidogyne spp. in laboratory conditions and the ability to prevent root-knot disease on tomato plants under greenhouse conditions. Experiment for testing parasitic ability on nematode eggs was followed a completely randomized design with 21 treatments and 3 replicates in the laboratory. The results showed that after 72 hours of after fungal inoculaion, 5 fungal isolates CTMT1, CTMT5, CTDL3, M3.1, ST2 had a high rate of nematode parasited eggs over 65%. Subsequently experiment for testing ability of these promising fungal isolates to prevent root rot caused by Meloidogyne spp. was conducted under greenhouse conditions; the experiment including 7 treatments and 3 replicates. Result found that five treatments corresponding applied 5 fungal isolates at 3.1 x 104 fungal spores per gram of soil and chemical treatment (active ingredient Abamectin) were expressed reduction of number of root-knot, the number of nematodes in the soil and roots, in which 3 fungal isolates CTMT1, CTDL3 and M3.1 expresed better efficacy in controlling root-knot nematode equal chemical Abamectin. Identification of these fungal isolates based on morphologicals and their sequence of ITS regions, 3 fungal isolates CTMT1, CTDL3 and M3.1 were Mucor irregularis, Purpureocillium lilacinum and Plectosphaerella cucumerina, respectively.