Abstract: Reported in this paper are chromosome numbers of six species of Mnium from Qinling Range． The chromosome number of M． pseudolycopodioides，n=6，is reported here for the first time． The counts for M．marginatum and M．lycopoidioides，n=12 and n＝6 respectively，agree with the previous reports，and those for M．laevinerve，M．heterophyllum and M．thomsonii，here all found to be n=6，differs from some or all previously published chromosome numbers for these three species．

Key words: Mnium, Mitosis, Meiosis, Chromosome numbers