Abstract: The meiosis and chromosome behavior of microsporocytes in Populus adenopoda were studied by aceto-carmine squash technique.The meiosis of the pollen mother cells of P.adenopoda showed a high correlation to external characters of male flower buds/inflorescences and anther color.The normal behavior of chromosome indicated a high degree of homology among the homologous chromosomes of P.adenopoda.However,the appearance of paralleled spindles at metaphase Ⅱ may result in big pollen grains.The varied number of nucleoli during meiosis of microsporocytes was probably due to ancient polyploid origin of Populus.The differences in the processes of meiosis in P.adenopoda occurred not only in different buds,but also in different parts of the flower bud.This meiosis asynchronicity was an important character of evolution for environmental adaptation during sexual reproduction of the genus.