The number of chromosomes in Taraxacum antungense was calculated by a root tip squashing method.The ploidity was analyzed by karyotyping and chromosome behavior observation during the meiosis process of pollen mother cells.Results showed that:(1)The number of chromosomes in T.antungense was 32.Its karyotype was formulated as 2n=3x+x′=32=（18m+6sm）+(3m+4sm+1T),which indicates a Stebbins’ 2A type.(2)The meiosis in T.antungense undergoes simultaneous cytokinesis.(3)Some of the chromosomes were found not to rank at metaphase plate in metaphase Ⅰ and metaphase Ⅱ cells.In anaphase Ⅰ and anaphase Ⅱ cells,observed some abnormal events including lagged chromosomes,chromosome bridge and fragment.During anaphase Ⅱ and telophase Ⅱ chromosome segregation was not synchronous and equal.At tetrad stage,dyad,triad,tetrad with micronucleus and polyad appeared.(4)The pollen germination rate in vitro was only 26.3%,which indicated that abnormal meiosis of PMCs was the cytogenetic reason of fertility reduction of T.antungense pollen.