Abstract: Plant growth and development is generally controlled by selective removal of short-lived regulatory proteins. One major pathway is represented by the ubiquitin (Ub)/26S proteasome pathway.In this pathway, ubquitin and 26S proteasome play essential roles. Ub is attached to proteins destined for degradation by a 3-step enzymatic (E1-E2-E3) conjugation cascade, and the resulting Ubprotein conjugates are then recognized and degraded by the 26S proteasome. The arm repeat-containing 1 (ARC1) and the skp1-cul1-F-box (SCF) proteins, belonging to the family of E3 Ub ligases,function in both the sporophytic and gametophytic self-incompatible responses, respectively. This review highlights the recent progress toward understanding the role of the Ub/26S proteasome pathway during self-incompatible responses.