The dietary effect of conjugated linoleic acid (CLA) on the response of the immunoglobulin (serum and tissue) production in Balb/C mice was examined at three doses: 0 %(control), 0.5% and 1.5%. The combination effects of CLA with vitamin ADE or selenium also were investigated. CLA at 0.5% increased serum immunoglobulin A, G, mesenteric lymph node (MHN) and gut luminal IgA (secretory IgA) levels. However, 1.5% CLA decreased SIgG slightly. CLA both alone and combined with vitamin ADE and selenium did not affect serum IgE. The levels of immunoglobulin concentration in the 0.5% CLA group were higher than those in the 1.5% CLA group. The level of serum IgG in 1.5% CLA combined with selenium was maintained at the same level as that of control. It is considered that over- doses of CLA (1.5%) even depressed the production of immunoglobulin but selenium and/or vitamin inhibited this activity to a certain extent. In this study, dietary CLA increased immunoglobulin production in a dose-dependent manner. Vitamin ADE and Selenium combined with CLA also increased the immunoglobulin production response except serum IgE.