Objectives. The purpose of this study was to develop an immunocytokine for immunotherapy of human ovarian cancer. Methods. The single-chain Fv of a monoclonal antibody, COC183B2, specific for an ovarian carcinoma-associated antigen (OC183B2), was genetically fused with the coding sequence of interleukin 2 (IL-2). The fusion protein, also called immunocytokine, IL-2-183B2scFv, was expressed in CHO cells and examined for its specificity and biological function. Results. The immunocytokine, IL-2-183B2scFv, retained the functions of both the antibody and IL-2. It was able to target IL-2 to tumor cells that overexpress OC183B2, and stimulate the proliferation of an IL-2-dependent cell line, CTLL-2. Conclusions. The IL-2-183B2scFv maintains the functions of both IL-2 and antibody. It can be potentially used for immunotherapy of ovarian cancer by delivering a high concentration of IL-2 to OC183B2-expressing ovarian cancer cells.