Chemical composition and contents of carbohydrates, lignin, and extractives in Moso(Phyllostachys pubescens Mazel), Henon(Phyllostachys nigra var. henonis Stapf ex. Rendle), and Timber bamboo(Phyllostachys bambusoides Sieb. et Zucc.) known as economically valuable bamboo species in Korea were analyzed as a function of ages. All of tested bamboo species were composed of fucose, arabinose, rhamnose, galactose, glucose, xylose, and mannose. Glucose was the sugar which showed the highest content followed by xylose. The contents of others were below 3%. Sugar contents of bamboo shoots showed the lowest among the tested bamboo samples, and the constant rates were shown after 50 days of growth. Lignin content increased by the growth of one year, and the increasing rates tended to be constant after the growth of three years. Bamboo shoots have the highest contents of acid-soluble lignin, which turned into insoluble lignin after the growth of 50 days. Bamboo shoots showed the highest content of extractives and tend to be decreased by the growth of 50 days and then the content increased slowly in proportion to the period of bamboo growth. No relationship was found between species and chemical composition of bamboo. However, there were significant difference in chemical composition between bamboo shoots and 50-day old bamboo.