With an aim of the genetic dissection of anther and pollen development, we identified an Arabidopsis mutant line named zy1511 by ethyl-methane sulphonate (EMS) mutagenesis. Genetic analysis indicated that the mutant phenotype was controlled by a single recessive nuclear gene zy1511. Cytological studies of anther at various developmental stages indicated that the mutant anther tapetum did not start degenerating after microspores released from the tetrads. Part of the mutant anther tapetum still existed at late stages of anther development, indicating that mutant tapetum degenerated later than that of the wild-type. So the mutant microspores could not develop into normal pollen grains in the anther. For the further genetic analysis and the map-based cloning of gene zy1511, we have mapped it to a region of 134 kb between molecular markers F25P12 and T8L23 on chromosome 1 using a map-based cloning strategy. As no male sterile genes have been reported in this region, we believe that zy1511 is an undiscovered key gene involved in pollen development.