Abstract: Use of an ubiquitination pathway-related factor, its agonist or antagonist in the preparation of a composition for regulating FOXP3, IL-2, and/or IFN-? activity, in which the ubiquitination pathway-related factor is selected from: Toll-like receptor, ubiquitin ligase, pro-inflammatory cytokine family receptor, and/or its coding sequence. The new type of regulatory factors can regulate regulatory T cells and immune system by regulating FOXP3, IL-2, and/or IFN-? activity. The regulatory factors and their derivatives can also be used as immunoadjuvant for treating or preventing major diseases (such as, infectious diseases and tumor, etc).