Abstract: The biomass structures of different stands of Phyllostachys heteroclada were studies by the allometric method based on 18808 bamboo culms, 47 rhizome quadrats and 38 samples of bamboo of different ages (1—6 yrs.) and diameter classes (0.5—3.0) from 39 sample plots. The biomass of culm, branch-leave and rhizomes in relation to diameter breast height fit out the regression equation by statistical procedures.The results obtained show that the total above ground biomass increases with the increase in diameter classes, and the distribution of the ratios of culm weight at different diameter classes to the total stand weight is as follows: 16% for 1.5 diameter classes, 30.5% for 2.0 classes, 26.1% for 2.5 classes and 16.0% for 3.0 classes, respectively. The total above ground biomass decreases with the increase of the age class and the distribution is 31.7% for age class Ⅰ, 22% for age class Ⅱ, 17.5% for age class Ⅲ, and 28% for age class Ⅳ or above.A. high-yield stand is defined as: vigorous rhizomes 50—60%; rhizome capacity 2.0—2.5‰, ratio of total above ground weight to total under ground weight 1.0—1.5; leaf area index 4—6; yield 4000—7000 jin per mu.