BACKGROUND: The DNA DNA fingerprinting of Mycobacterium tuberculosis with RFLP is very a useful tool for deciphering the molecular epidemiology of tuberculosis. Since standardization of RFLP methodology using Pvu-II restricted IS-6110 has been proposed international comparison of the RFLP pattern became possible, and some predominance of RFLP pattern in the East Asia was noticed. An international comparison of the RFLP pattern became possible with the proposal to standardize RFLP methodology using Pvu-II restricted IS-6110, and the comparison has noted some predominance of RFLP pattern in East Asia. We studied (The) RFLP patterns of tuberculosis strains collected in at SNUH was studied and was compared them with with the strains from another East Asia strains other strains from East Asia. METHOD: Fifty strains of M.tuberculosis were isolated from patients who visited or were admitted to the SNUH in 1998. We also received some isolates that belong to Beijing family. Some isolates belonging to the Beijing family were also received. After the extraction of DNA from M. tuberculosis isolates, the chromosomal DNAs were digested with Pvu-II, and we analyzed them by and analyzed by the Southern blot method with DNA probe to IS6110. RESULT: There were 6 strains that belong to Six strains belonged to the Beijing family. And The RFLP patterns of another other 9 strains were similar to each other. There were no No statistically significant differences among the groups in terms of age, sex, drug resistance, endobronchial tuberculosis, having presence of underlying disease, and the province they live of residence were found. CONCLUSION: There were a few Few groups of M. tuberculosis strains in from SNUH that (delete) showed similar RFLP patterns. But, their clinical meaning is not clear yet., but their clinical implications are not yet clear.