Purpose14 loci on chromosome 13 were examined to detect loss of heterozygosity(LOH) in 20 cases of glioblastoma (GBM) in order to locate the deletion areas probably harboring tumor suppressor genes(TSGs).MethodsPolymerase chain reaction (PCR) based microsatellite polymorphism analyses were performed to detect LOH on chromosome 13, fluorescence-labeled primers and Perkin Elmer 377 DNA Sequencer were applied.Results60 % informative cases of GBM displayed LOH on chromosme 13. 60 % of informative cases displayed LOH on 13q and 27% on 13p. 45.8% of informative loci showed LOH in our series, in which the higher frequent LOH were observed in the chromosomal regions from loci D13S217 to D13S263 on 13q12-14.2 and from D13S156 to D13S265 on 13q21.2-32 and at loci D13S153 on 13q14.1- 14.3 Conclusions Loss of genetic material on chromosome 13 may play an important role on the molecular pathogenesis of GBM. The chromosomal regions from loci D13S217 to D13S263 on 13q12-14.2 and from D13S156 to D13S265 on 13q21.2-32 and at loci D13S153 on 13q14.1-14.3 may harbor several TSGs associated with GBM, which may include novel TSGs apart from RB1.