Two series of Ak samples, one collected at random from ten different sources at the flowering stage and the other at various stages of maturity had earlier been studied for a number of physical characteristics (14). The series were now investigated for major chemical characteristics. Their hollocellulose, a-cellulose, lignin, pentosan and contents were determined. Also, losses due to alcohol-benzene solubility, a-hydrolysis, B-hydrolysis and acid purification were examined in these samples.