The regulatory cells play important roles in anti-tumor immune response. Among these cells, CD4+CD25+ regulatory T (Treg) cells and CD8+CD28- cells are well-documented. CD122, IL-2/IL-15 receptor β chain, is preferentially expressed on the CD8+CD28- cells. Since the status of CD122 expressing CD8+ cells have not been known so far in cancer patients, we investigated CD8+CD122+ cells in peripheral blood of advanced stage cancer patients. Flow cytometry was used in the study. Monocyte counts were higher; red blood cell (RBC) counts, hemoglobin, and hematocrit were lower; other hematological parameters were similar in cancer patients compared controls. CD122 expression of CD8 lymphocytes and CD8+CD122+ cell number are not different in advanced stage cancer patients and controls. Although CD122 is expressed on CD8+CD28- cells which increase in cancer patients, CD8+CD122+ cells is not different between cancer patients and healthy subjects. Ongoing researches which studies with other regulatory cells and cytokines in tumor microenvironment are needed.