AIM： To study the effects of nabumetone on immunological fuctions in mice METHODS： After nabumetone was given ig to mice， the weight of thymus and spleen， phagocytizing function of macrophages， PHA－ induced lymphocyte transformation were observed respectively in mice RESULTS： The weight of thymus and spleen was decreased， the phagocytizing function of macrophages was reduced， PHA－ induced lymphocyte transformation was markedly inhibited with nabumetone in mice CONCLUSION： The immunological function in mice was significantly inhibited with nonsteriod anti－ inflammatory drug－ nabumetone