10.18170/DVN/XPECRU Center for Bioinformatics(Peking University) Peking University Open Research Data Platform 2015 Access to Data CVTree constructs whole-genome based phylogenetic trees without sequence alignment by using a Composition Vector (CV) approach. It was first developed to infer evolutionary relatedness of microbial organisms and then successfully applied to viruses, chloroplasts, and fungi. It circumvents the ambiguity of choosing the genes for phylogenetic reconstruction and avoids the necessity of aligning sequences of essentially different length and gene content. The new features of this CVTree update include:  the inbuilt database has been enlarged and is now updated monthly from the NCBI FTP site Sayers et al. (2009).  Users may upload sequences of their own and carry out phylogenetic study together with genomes selected from the inbuilt database.  Many kinds of tree files are provided to facilitate comparison with taxonomy. Some tree files are directly uploadable to MEGA Tamura et al. (2007) or the Interactive Tree Of Life (iTOL) project Letunic and Bork (2007) in order to display the results in different ways.  The efficiency of CVTree has been significantly enhanced to meet the requirement of treating thousands of genomes in a single run. Lei Kong(Center for Bioinformatics , Peking University)