According to the definition of cytokine, the direction of signaling should be from cytokine to receptor. The counter receptor was presented. Membrane bound macrophage colony-stimulating factor (m-M-CSF) and its receptor (M-CSF-R) were shown in human leukemic cell line J6-1 as autojuxtacrine mechanism. Soluble M-CSF receptor (sM-CSF-R), which was isolated from J6-1 cells membrane, was added into J6-1 cell culture. It was observed inhibition of J6-1 cell proliferation, decreasing of mitosis index and ratio of multinuclear cells, enlargement of cell diameter and volume, down regulation of numerous surface antigens. Dramatic change of intracellular pH was shown between several min to 20 min after treatment of sM-CSF-R. It suggested that some information was transmitted via m-M-CSF from sM-CSF-R. This counter signaling was not influenced by saccharification of m-M-CSF. According to the definition of cytokine, the direction of signaling should be from cytokine to receptor. The counter receptor was presented. Leukemic cell line J6-1 as autojuxtacrine mechanism. Soluble M-CSF receptor (sM-CSF-R), which was isolated from J6-1 cell membrane, was added into J6-1 cell culture. It was observed inhibition of J6-1 cell proliferation, decreasing of mitosis index and ratio of multinuclear cells, enlargement of cell diameter and volume, down regulation of numerous surface antigens. Dramatic change of intracellular pH was shown for several minutes to 20 min after treatment of sM-CSF-R. It suggested that some information was transmitted via mM-CSF from sM-CSF-R. This counter signaling was not affected by saccharification of mM-CSF.