Abstract： Objective:To study the value of detection of rpsl gene mutation in streptomy cin(SM)-resistance in clinical isolates of mycobacterium tuberculosis by PCR -SSCP,and to expect to set up a r apid detective method of rpsl gene mutation in mycobacterium tuberculosis,Method Eighty seven specimens isolated from patients were detected by PCR-SSCP silver staining,and using strain H 37Rv as a control,Results In 87 mycobacterium tuberculosis clinical isolates,the r psl DNA fragments from 16 drug-susceptible isolates had no mutation in rpsL gene ,48 of 62 sputum specimens showed rpsl gene mutation by PCR-SSCP,positive rate w as 77.4%.Conclusions The rpsL gene mutation is an important molecular mechanism of M.tuberc ulosis resistance to SM.PCR-SSCP might become a rapid detecting method of SM-r esistance of M.tuberculosis.