PURPOSE: A method for preparing lymphocytes including natural killer cells and a pharmaceutical composition containing the lymhocytes for targeting cancer cells are provided to treat cancer in which HER2/neu antigen is expressed.CONSTITUTION: A method for preparing lymphocytes including natural killer cells for targeting cancer cells which expresses HER2/neu antigens comprises: a step of adding a culture medium containing a natural killer cell surface protein antibody, serum, and interleukin-2 to a culture container coated with immunoglobulin G and culturing monocytes isolated from peripheral blood; and a step of treating anti-HER2/neu antibody to the culture medium and culturing.COPYRIGHT KIPO 2012본 발명은 면역글로불린 G 존재하에서 단핵구 세포를 배양함으로써 인터페론-γ 생성능이 현저하게 증가된 NK 세포를 포함하는 림프구에 항-HER2/neu 항체를 결합시킴으로써, 유방암, 난소암 등의 HER2/neu 항원을 발현하는 암세포로의 표적지향을 위한 자연살해 세포를 포함하는 림프구의 제조방법 및 이를 포함하는 암세포 표적지향을 위한 약학 조성물을 제공한다.