Abstract: Developmental anatomy and chemical analysis including isolation and characterization of some important constituents in the bark of Populus tomentosa Carr.were investigated.The basic structure of tissues and cells produced from the primary and secondary growth of this bark was described.Attention was paid to the seqential changes of thses structures, initiation of the periderm,late-formed rhytidome and the retention of the cortical region,seasonal activity of secondary phloem,and the variable surface configuration of trunk,which were traced from those in the young shoot through the aging of matured trees,Successive extraction by neutral solvents,1% sodium hydroxide,cellulose and the individual sugars,“lignin”and its methoxyl content,formaldehyde reactive phenolic acid,etc.were determined.Chlorophyll in the outer bark,two pure glucosides,a salicin and another not yet identified,five phenolic acids such as p-hydroxybenzoic acid,p-cureeric acid,syringic acid,ferulic acid,and vanillic acid,were analysed by common methods,isolated and characterized by chromatography,infra-red absorption spectrum and high pressure liquid phase spectrum.Isoenzymes from the male and female tree bark were compared by electrophoresis.Besides this species studied,about six other species of Populus were compared in the concerned problems for reference.This report is a brief summary in nature for the accumulated studies carried on intermittently during the past decade. It may fill a gap in the study on growth and development of trees in Populus, and it may also be considered as a basic step towards the physiological or biochemical approch for the related problems,at least in static concept of the end products in a living tree.The results of this study would provide some basic information for the evaluation of the possible utilization of such barks. Discussion about this study and the related problems in bark research was made briefly.Some interest findings worthy for intensive study are carrying on.Further results will be presented elsewhere.