Taxonomic trees are an effective way to represent taxonomists’ views on biodiversity. There are numerous different taxonomic trees to be used in various biodiversity informatics projects. To document the differences and to integrate biodiversity information from different sources, methods and related tools for comparing taxonomic trees are required. This presentation proposes a novel and explicit definition for taxonomic tree comparison based on mathematical set theory and two indexes to describe the similarity of two trees. One is Node Index,  the other is Structure Index. Based on the analysis methods defined here, a platform for classification analysis - Taxonomic Tree Tool - is developed, which allows users to upload, build up and maintain their own trees, compare trees in their working space and public space, visualize results, and export them to standard files. A website for the platform has been set up and opened to taxonomists around the world.