Abstract: In order to quickly estimate the biomass of economic stem wood of Bambusa distegia stand (hereinafter referred to as “economic wood weight”), 1-4a⁺ age materials of Bambusa distegia was selected from plots with different site conditions in Xuyong county, regression model of economic wood weight and its application were studied. It was found that the economic wood weight of 2a and 3a was higher and the water content was lower, which was suitable for selective cutting. By comparing the variation of economic wood weight of individual plant with different DBH classes, it was concluded that the cultivation of large-diameter bamboo was an effective way to increase the yield of bamboo forest. The correlation of DBH, plant height, length of bamboo joint at height of DBH with economic wood weight was studied, and it was concluded that DBH could be used as a better variable to construct the economic wood weight model of a single plant of Bambusa distegia. The estimation models of economic wood weight were constructed by the methods of unary linear regression, multiple linear regression and curve regression respectively then were optimized. Finally, 1 whole age model and 4 age distinction models were formed. The model was used to estimate the wood weight per unit area of stand under different site conditions, and compared with the actual economic wood weight, it was concluded that the estimated value of age distinction model was more accurate than that total age model. The relationship between economic wood weight and average age, average DBH, altitude, stand density, sunshine and moisture conditions was analyzed. It was found that the average bamboo age was closer to 3a, the larger the average DBH was, the lower the altitude was, the better the moisture condition was, and the higher the economic wood weight was. There was no significant correlation between economic wood weight and stand density and sunshine. It was suggested that the age structure ratio of 1a:2a:3a:4a⁺ should be kept at 3:3:3:1.