〔Abstract〕 Objective To detect the expression of serum exosomal miR-30d-5p in occupational dermatitis medicamentosa-like of trichloroethylene(OMDT) patients and its correlation with liver function, then perform bioinformatics analysis and verify the target gene. Methods Serum exosomes were extracted from 6 OMDT patients and 6healthy controls, and miRNA was extracted from exosomes which were identified by transmission electron microscopy, nanoparticle tracking analysis and western blotting.The expression of serum exosomal miR-30d-5p was detected by real-time fluorescence quantitative PCR,then the correlation with liver function was analyzed.The target genes of miR-30d-5p were predicted by the miRWalk and miRBD databases.Gene ontology analysis and KEGG pathways analysis were performed.Finally, RHOB was verified by Dual-luciferase reporter assay. Results The expression of serum exosomal miR-30d-5p significantly decreased in 6 OMDT patients at the peak of the disease(P<0.05),and it was negatively correlated with the level of AST,ALT and GGT(correlation coefficient:r s =-0.943,P=0.005;r s =-0.886,P=0.019;r s =-0.886,P=0.019). Bioinformatics analysis and dual-luciferase reporter assay showed that RHOB was the target gene of miR-30d-5p. Conclusion The expression of serum exosomal miR-30d-5p decreases in OMDT patients, which is negatively correlated with the level of liver function, and the target gene RHOB may be involved in the process of liver injury induced by trichloroethylene.