Thirteen vitamins, twenty amino acids, hormones, inorganic salts, and other chemical agents, which constitute typical serum-free media, were evaluated for the development of fortified medium to enhance cell growth and productivity of recombinant antibody in the cultures of the recombinant Chinese hamster ovary (rCHO) cells. Two different rCHO cell lines, rCHO-A producing recombinant antibodies against the human platelet and rCHO-B secreting recombinant antibodies against the S surface antigen of Hepatitis B, respectively, were cultivated in batch suspension mode. Concentration of interested component in the tested medium was doubled to examine the fortification effect. Growth of rCHO-A cell and its antibody production were slightly improved with addition of either choline chloride, folic acid, thiamine(.)HCl, or Long (TM) R(3)IGF-I. On the other hand, in the cultivation of rCHO-B cell which was more sensitive to its environmental changes, hormones such as Long (TM) R(3)IGF-I and triiodothyronine (T-3) as well as various vitamins involving choline chloride, i-inositol, niacinamide, pyridoxine HCl, and thiamine(.)HCl enhanced the cell growth and antibody production. Particularly, when concentration of consuming amino acid was doubled, remarkable increase in specific productivity was served, resulting in high final antibody concentration. These results were believed to provide a fundamental strategy of medium fortification useful for improvement of recombinant antibody production in serum-free medium.