This study was carried out to develop antitumor effect of the n-butanol soluble fraction of Perilla frutescens on (KB cells) human oral epitheloid carcinoma cells. The cytotoxictty of methanollc extract of Perilla frutescens on KB cells was evaluated by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide(MTT) assay. The antitumor activity of various fractions obtained from n-butanol soluble fraction of Perilla frutescens was evaluated in human oral epithelold carcinoma cells. The antitumor acavity of the n-butanol soluble fraction on human oral epitheloid carcinoma cells was evaluated by MTT assay of colorimetric method. The light microscopic study was carried out to observe morphological changes of cultured human oral epitheloid carcinoma cells. These results were obtained as follows; 1. The fractions 1,2 and 3 of the n-butanol soluble fraction of Perilla frutescens were shown significant antitumor activities. 2. The number of human oral epitheloid carcinoma cells were decreased and tend to form cell cluster by treatment with fractions 1,2,3 and 4 of the n-butanol soluble fraction of Perilla frutescens. 3. The fraction 1 of the n-butanol soluble fraction of Perllla frutescens showed the highest antitumor activity on Perilla frutescens. It has been selected as a lead fraction for further examinations.