本文主要是对尾叶桉U6(E.urophylla U6)采用胸径与树冠投影面积,树高与树冠投影面积,胸径、树高与树冠投影面积推导相关理论树冠投影面积。经进行相关检验,方差分析和精度估算,结果如下:胸径与树冠投影面积的回归方程效果最佳,r=0.95045,相关显著性甚高F=249.49298**,估测精度高达99.50%,达一级水平;其次是胸径、树高与树冠投影面积,R(D-H-S)=0.94937,相关显著达极高水平F=246.37436**,估测精度99.50%,高达一级水平;次之是树高与树冠投影面积,r=0.85718,相关显著性水平也极高F=122.51797**,估测精度也高达一级水平,精度为99.10%。并经作标准回归系数检验,检验结果表明:胸径对树冠投影面积的影响所起的作用远远大于树高所起的作用。所推导的三个树冠投影面积回归方程在本林区适用,而最优解且最简便的是胸径与树冠投影面积的回归方程。以上三个回归方程可为尾叶桉U6(E.urophylla U6)人工林进行抚育间伐的设计与施工提供理论依据。 In this paper, the theoretical crown projected area of ​​E.urophylla U6 was deduced from the DBH crown area, crown height and canopy projected area, DBH, tree height and canopy projected area. The results of correlation test, analysis of variance and accuracy are as follows: The regression equation between DBH and crown projected area is the best, r = 0.95045, the correlation is very high F = 249.49298 **, the estimation accuracy is up to 99.50% (DHS) = 0.94937, the correlation was significant at very high level F = 246.37436 **, the estimation accuracy was 99.50%, up to the first level; the next was the height at the height of the tree Crown projection area, r = 0.85718, the correlation level is also very high F = 122.51797 **, the estimation accuracy is also up to a level with an accuracy of 99.10%. And by the standard regression coefficient test, the test results show that: the diameter of the canopy crown area of ​​the role played a far greater role than the tree height. The deduced three regression equations of canopy projection area are suitable for this forest area, and the optimal solution and the most convenient one is the regression equation of DBH and canopy area. The above three regression equations can provide a theoretical basis for the design and construction of thinning of E. urophylla U6 plantations.