The study of cornified cell envelope has been used to investigate the differentiation factors and to advance oral carcinogenesis, CE of human oral keratinocytes are in wet condition as saliva containing many proteases, growth factors, and many kinds of bacteria, The analysis of CE in Immortalized human oral keratinocyte(IHOK) derived from normal human oral keratinocyte(NHOK) will be used to study the pathogenesis of oral squamous cell carcinoma, The purpose of this study was to analyze the amino acid component derived from CE of cultured NHOK and IHOK, It will be helpful to study the role of transfected E6/E7 gene in forming CE, and to examine the pathogenesis of oral squamous cell carcinoma, After primry culture of NHOK, IHOK were cultured in KBM bullet kit at 370C under 95% C02 incubator, Growth curve according to calcium concentration, cornified cell envelope measurement(CEM), and protein chemistry for amino acid component of CE were done(Mena :f::SD) , respectively. The obtained results were as follows, lHOK showed small areas of stratification, more compact, with irregular border and tightly apposed cells in 1,2 mM Ca++, Cornified cell envelope exhibited an aggregated group of empty space surrounded by the remained cell membrane, During the terminal differentiation in cultured NHOK and IHOK, insoluble cornified cell envelope formation was increased, CEM of NHOK was about 4 folds than that of lHOK under high calcium, Amino acid component of both groups showed Pro/Glu(SPR) , Gln/Glu(lnvolucrin) , and Gly(Loricrin) in descending order, From the aboving results, ít was suggested that when the terminal dífferentiation in cultured NHOK and IHOK, major amino acid component of CE in cultured lHOK was the same to that of cultured NHOK, It was thought that E6 and E7 gene should be involved in preventing the differentiation and proliferation of IHOK from making CE,