To identify rice mutants of floral organ and seed development,a rice mutant library of T-DNA insertional mutagenesis constructed by the national key laboratory of crop genetic improvement at Huazhong Agricultural University was screened on large scale.A large number of useful information of mutants were got.Among 9 760 stable lines of phenotype variant,177 lines showed morphology and number change of floral organ,with mutation frequency of 1.81%; 179 lines from the 3 432 lines showed abnormal seed development,the percent of mutants was 5.22%.270 lines of phenotype variant interested were obtained and 175 lines showed T-DNA insertion through PCR test,the positive rate was 64.8%,which will lay the foundation for cloning genes related with rice floral organ and seed development.One low seed-setting mutant was identified and confirmed to be cosegregated with its corresponding T-DNA flanking sequences tags,providing an important genetic resource for further studying the function of this gene.