The ubiquitin-proteasome pathway is responsible for the degradation of most cellular proteins in eukaryotes.It regulates almost all cellular activities, including cell proliferation, differentiation, apoptosis, gene transcription, and DNA repair.The dysfunction of the ubiquitin-proteasome pathway is associated with the pathogenesis of numerous human diseases, including cancer and neurodegenerative diseases.The marketed proteasome inhibitors have been successfully used to treat multiple myeloma and mantle cell lymphoma.Furthermore, novel inhibitors against the components of the ubiquitin-proteasome pathway are under developed and exhibit promising therapeutic effects in vivo.This paper will briefly introduce the progress on the drug discovery related to the ubiquitin-proteasome pathway.