Abstract: In this paper, a bioassay method involving the interleukin 6 dependent murine hybridoma B9 cell line was used to detect the level of released and cell-associated interleukin 6 in resident peritoneal macrophages from the mouse. The phorbol ester, phorbol 12-myristate 13-acetate(PMA), the calcium ionophores A₂₃₁₈₇, the chemotactic peptide fMLP and lipopolysaccharide(LPS) were introduced in these experiments as stimulators. PMA, A₂₃₁₈₇ and fMLP were shown to induce a dose-dependent increase of both released and cell-associated interleukin 6, whereas, LPS caused increase of interleukin 6 activity in supernatants of cultured peritoneal macrophages of the mouse. The effects of PMA and A₂₃₁₈₇ suggested that the pathway of PKC and calcium is involved in the production and secretion of interleukin 6. The effects of fMLP and LPS provided evidence that they participated in the process of inflammation. The difference between LPS and the other three stimulators in cell-associated interleukin 6 activity might suggest a different mechanism of actions of generation of interleukin 6.