Whole histone and histone fractions from calf dental pulp have been studied. Histones were extracted and fractionated according to the method of Johns and Phillips. The histone fractions were further purified by a polyacrylamide gel electrophoresis. The yield of whole histone recovered was 668 mg per 100 g of dental pulp. This is very large amount as compared to the calf thymus and liver. However, nearly similar amount was obtained from transplantable ascites carcinoma cells. Quantitative differences were found between a number of corresponding histone fractions of calf dental pulp and thymus. Striking low contents of fraction f2a1 (arginine-rich histone) were observed in dental pulp, being about one third of those of calf thymus. Fraction f2a2 was also significantly decreased. However, slightly higher contents of histones were found in fractions f1 and f3 plus f2b. The electrophoretic behaviors were compared with those of histones from calf thymus and rat liver. Amino acid analysis of the individual histone fractions showed that the over-all compositions were remarkably similar to those of corresponding fractions from calf thymus. The data of comparable histone fractions of calf and rat isolated by other workers have been included for comparison. The evidence for the tissue-specific differences in the distribution of the histone fractions among different tissues of the single animal was presented.