Objective To study the relationship between mutation of rpsL drug-resistant gene in L-forms of Mycobacterium tuberculosis and drug-resistance to streptomycin in pneumoconiosis patients.Methods A total of 52 clinical isolated strains of Mycobacterium tuberculosis L-forms were collected from 97 pneumoconiosis patients.The mutation of rpsL gene was detected by PCR-SSCP,and the drug-resistance to streptomycin was performed by routine antimicrobial susceptibility test(AST).Results The results of drug susceptibility test showed that 26 in the 52 clinical isolated strains were drug-resistant to streptomycin.The streptomycin-resistant rate was 50.00%(26/52).The gene mutation rate of rpsL detected by PCR-SSCP was 40.38%(21/52).The coincidence rate of two experimental results was 80.77%(21/26).Conclusion High detectable rate of streptomycin-resistant strains in Mycobacterium tuberculosis L-forms was found by PCR-SSCP.The application of PCR-SSCP may possess important value for guiding clinical medication of pneumoconiosis patients complicated with tuberculosis among coal workers