Among the plant protein sources the seed play an important role owing to the presence of large amount of storage protein. Rice has the highest nutritional value among the cereal protein due to the high content of essential amino acid. Large number traditional cultivars in Assam are having high protein and essential amino acids content which is important for synthesize other some of the amino acids. Present study has been undertaken to characterize the seed protein of few indigenous cultivars of rice (Oryza sativa L.). All six (6) cultivars showed significant variation in total protein content, total amino acid, Methionine, Tryptophan Lysine & fibercontent. Total amino acid content showed positive correlation with protein content.In the present study, the cultivar having high grain protein show thicker bands in SDS -polyacrylamide gel electrophoresis than the cultivar with low protein content.