In many cases, the function of Xenopus gene is inferred by the genomic data of other species, such as human, mouse, and zebrafish, due to their high level of conservation. However, although now the Xenopus community has a very good quality of genomic resources, surprisingly, still the identification of human ortholog is challenging. By utilizing the genome of 10 vertebrate species across taxa, and transcriptome of several amphibian species, here I introduced the robust method to identify orthologous gene family for Xenopus genes. Although two-thirds of all genes could be well assigned to a vertebrate-conserved orthologous gene family, the remaining one-third genes are not obviously called for their orthology. This limitation should be aware when the Xenopus data is analyzed with the resource of other species, such as the Gene Ontology terms of human.