Abstract: Objective To investigate the loss of heterozygosity (LOH) of fragile histidine triad(FHIT) and Ras association doma in family 1A (RASSF1A) gene and to analyze the relationship between the gene and clinicopatho logical characteristics of cervical carcinoma.Methods Two sites of FHIT and RASSF1A gene were selected.We used polymerase chain reaction(PCR) and perpendicular electrophoresis technique to detect LOH in 50 cases of cervical carcinoma and 40 cases of cervical in traepithelial neoplasia(CIN).Results For D3S1234 and D3S4103 of FHIT, the rates of LOH of CIN and CIN were 32.0% and 66.7%; for D3S4103 the rates of LOH of CIN was 24.0%, and that of CIN was 60.0%.The positive rates of LOH increased with the grades of CIN (P<0.05).At D3S1478 the rates of LOH was 12.0% for CINI, 53.3% for CIN, respectively.At D3S4604 the rates of LOH were 24.0% for CIN and 60.0% for CIN and the positive rates of LOH also increased with the grades of CIN (P<0.05).Conclusion The changes of FHIT and RASSF1A gene are relatively late events in cervical carc inoma.