Provided are a composition for culturing NK cells, and a method of culturing NK cells using the same. According to an aspect, in culturing NK cells from peripheral blood mononuclear cells, when NK cells are cultured in a medium including the composition for culturing NK cells, the composition including IL-15, IL-18, and IL-27, the NK cells may proliferate in large quantities and activation of NK cells may be promoted. Therefore, when the NK cells are used, cancer cell apoptosis or cancer cell-killing ability may be promoted. Accordingly, the NK cells may be used as an effective adoptive immune cell therapy product in cancer prevention or treatment.