The intense flow of human population can determine the number of non-native species by creating new dispersion routes. We examined if human population size determined the richness and phylogenetic diversity (Faith’s PD, mean pairwise distance, and phylogenetic eigenvectors) of non-native plants species in 62 cities globally distributed. Twelve non-native communities were phylogenetically clustered and five were phylogenetically overdispersed. Human population size did not affect the non-native richness or the phylogenetic diversity and composition. Due to the complexity of cities, other factors should be incorporated in future analysis to obtain greater clarity on the distribution and phylogenetic diversity of non-native species.