Six important genera of plant parasitic nematodes were found in three banana plantation Yunnan Province.They are Meloidogyne incognita , Helicotylenchus, Tylenchorhynchus, Hoplolaimus, Trichodorus and Hemicriconemoides. The genera Meloidogyne, Hoplolaimus and Tylenchorhynchus were found widely distributed in three plantations. M.incognita was a predominant species and present in the highest population density, occupying 63.88% of the total population in annual banana plantation, 75.16% in biennial banana plantation, and 52.15% in perennial banana plantation. Further studies indicated that M.incognita had distinctly seasonal fluctuation. It suggested that the population fluctuation was closely correlated with the average month temperature and rainfall.