(1) the inbuilt database has been enlarged and is now updated monthly from the NCBI FTP site (10). (2) Users may upload sequences of their own and carry out phylogenetic study together with genomes selected from the inbuilt database. (3) Many kinds of tree files are provided to facilitate comparison with taxonomy. Some tree files are directly uploadable to MEGA (11) or the Interactive Tree Of Life (iTOL) project (12) in order to display the results in different ways. (4) The efficiency of CVTree has been significantly enhanced to meet the requirement of treating thousands of genomes in a single run.