Abstract: Up to now, the information about elements analysis of several tropical woods, have not been found at home and abroad. Many scientists have thought that the reason why tropical woods processing difficultly is the high silican content in it. So that this paper investigates the chemical elemental distribution of several tropical woods and discusses the silican content emphaticaly. The study of theory of theory and experiment proves that siliceous concretions which used to be called in the form of density isn’t SiO2. If Woods sample are put in the HC1 solution, it becomes soft and easier to process. Elemental analysis may provide scientific basis for the tropical wood utilization.