Abstract: In order to comprehend the anatomical properties and search the interior mechanisms of wood property variations of Mytilaria laosensis plantation,and provide solid scientific basis for establishing serial pattern of the "culturing-wood properties-processing and utilizing",M.laosensis plantation wood was systematically studied on the anatomical properties and their radial variation patterns by using electronic microscope and micrograph analysis system of computer,and approaches of quantitative anatomy were used from a microscopic aspect.The results were as the followings:1) the average values of fiber length,width,wall thickness,ratio of length to width,wall thickness to cavity and cavity to width were 2 014.2 μm,26.19 μm,11.07 μm,78.68,0.79 and 0.57 respectively.From pith to bark,the radial variation patterns of all fiber morphological parameters were gradually increasing,except for the ratio of cavity to width was gradually decreasing;2) the average values of vessel element length,width,wall thickness,ratio of length to width,wall thickness to diameter and cavity to width were 1 666.0 μm,53.83 μm,5.44 μm,31.85,0.12 and 0.90 respectively.From pith to bark,the radial variation patterns of all vessel morphological parameters were gradually increasing,except for vessel wall thickness and ratio of wall thickness to cavity were gradually decreasing;3) the average proportions of fiber tissues,vessel tissues,wood ray tissues as well as longitudinal parenchyma were 54.8%,16.5%,27.6% and 1.1% respectively.From pith to bark,the proportion of fiber tissues was gradually increasing and that of vessel tissues was gradually decreasing,but the variation patterns of the proportions of wood ray tissues as well as longitudinal parenchyma were not significant;4) the average microfibrillar angle was 8.4° and its radial variation was gradually decreasing from pith to bark;5) the dividing line between juvenile wood and mature wood was the seventh year after planting.