With the methods of restriction fragment length polymorphisms(RFLPs) and Southern blot, we performed a molecular genetic study in 20 cases of intracranial meningiomas. There were four cases of invasive meningiomas, two cases of recurrent meningiomas and one case of central neurofibromatsis. Comparison of the alleles detected by DNA probes in normal versus tumor DNA revealed chromosomal alteration. The following probes were used : ESR(chromosome 6q), pYN22, pYNH37.3(chromosome 17p), cEFD52(chromosome 17q), D22S10, IGLC2(chromosome 22q). In seventeen of 20 cases(85%), constitutional heterozygosity was observed for IGLC2 probe on chromosome 22q and loss of heterozygosity was detected in nine of 17 informative cases(53%). There was no loss of heterozygosity for other probes. Three of 4 cases of invasive meningiomas and one case of central neruofibromatosis displayed loss of heterozygosity.