The immunomodulating activity of diucifon--activated and glutaraldehyde fixed human mononuclear cells (MNC-DGA) was studied in the test--system of autologous and allogenic mononuclear cells proliferative response. It was shown that MNC-DGA had the same stimulating activity as the diucifon treated unfixed cells. The immunomodulating capacity of MNC-DGA was fully abolished in the case MNC-DGA. So, the interaction between interleukin 2 receptor (Tac--antigen) and the membrane form of the mediator, expressed on MNC after diucifon treatment may play an important role in MNC-DGA immunomodulating activity. The regulating activity of MNC-DGA was revealed both in autologous and allogenic systems. The speculation is that construction of new immunomodulating drugs as complexes of cell-like carrier and immunomodulators fixed on their surface may be perspective.