Objective:To explore the expression pattern of zebrafish gene NOMO1 during early embryonic development. Methods:The zebrafish ortholog of the mammalian NOMO1 cDNA was cloned,and semi－quantitative RT－PCR was used to preliminarily detect the expression level of NOMO1 during the zebrafish embryonic development. At the last step,the expression pattern of zebrafish NOMO1 among the early stage of embryonic development was described by whole in situ hybridization. Results:cDNA of zebrafish NOMO1 is 3 924 bp,which contains a complete coding sequence of 3 626 bp. The expression of zebrefish NOMO1 is widely distributed from fertilization to 24 hpf(hours－post－fertilization),which is most abundantly transmitted in the endoderm and mesendoderm. After 24 hpf,the expression mainly concentrates on the nervous system,such as prosencephalon,mensencephalon,cerebellum,precordal plate,otic vesicles,eyes,and at somewhat lower level in heart. Conclusion:According to the expression pattern of NOMO1,NOMO1 may be required for the development of the zebrafish embryo, and influence the heart development during the early period.