I am reporting the identdficiation, expression patterns, and possible biological functions of zebrafishkif3a (kif3az) encoding 116 aminoacids. Kif3az contains various domains, such asthe kinesin motor domain, catalytic domain, KISc domain, and two coiled coil domain. Phylogenic analysis shows that kif3az shares high homology with the amphibian andmammalian homologues, suggesting that it is anevolutionary well conserved gene playing an essential biological role. Spatiotemporal expression studiesofkif3az found that itwas expressed maternally and zygotically.kif3az transcripts were evenly distributedin the blastomeres at 2-cellstage. Its ubiquitous expression throughouttheblastomerescontinuedtill40% epiboly. However,kif3az transcripts became restricted to the shield area,the structure corresponding toSpemann’s organizer of Xenopus embryos. At 80% epiboly stage, its transcripts were present in the distal forerunner cells.kif3az transcripts were found in Kupffer’s vesicle of the embryos at tailbud and 6 somite stages. At 13 somite stage,kif3az transcripts were present in the telencephalon,diencephalon, trigeminal placode, and somites. Such expression pattern was intensified in the telencephalon, diencephalons, hind brain, pronephric ducts, optic vesicles, and spinal cord neurons in the 23 somite stage embryos, and last till 24 hpf. I discussed possible functions of Kif3az in the vertebrate embryonic development.