Objective:To investigate the effect of histone deacetylation modification on early embryogenesis and three germ-layer diffierentiation of Xenopus laevis. Methods:Two-cell embryos were treated with 400 nmol/L Trichostation A(TSA)to observe early embryogenesis and expression of three germ layer marker genes by whole-mount in situ hybridization. Micro-injection of histone deacetylase 1(HDAC1)specific antisense oligonucleotide(HDAC1MO)was performed to knockdown HDAC1. The expression of three germ layer marker genes was detected by whole-mount in situ hybridization. Results:Embryos treated with 400 nmol/L TSA showed developmental defects. The expression of three germ layer marker genes were affected in embryos treated with TSA or knockdown of HDAC1. Conclusion:Histone deacetylase is involved in germ-layer differentiation during early embryogenesis.