Objective:To investigate effects of ETS1 on early embryo development of Xenopus laevis. Methods:The pCS2+-ETS1 plasmid was produced by ligating pCS2+ plasmid and ETS1 cloned according to PCR. The expressions of the ETS1 during embryogenesis were detected by RT-PCR and Western blot. After micro-injection of ETS1 mRNA into embryo,the expressions of marker genes of different embryonic layers were detected by whole mount in situ hybridization and quantitative RT-PCR. The effect of ETS1 over-expression on apoptosis and proliferation of cells was analyzed by Western blot. Results:The expression of ETS1 started from the period of oosperm,and increased through all periods of organogenesis. The overexpression of ETS1 inhibited differentiation of cells and expression of marker genes of mesoderm and ectoderm in neurulation. The expression of apoptosis-related proteins was increased,whereas the expression of proliferation-related proteins had no significant change. Conclusion:ETS1 is expressed through all periods of embryogenesis of Xenopus laevis. The overexpression of ETS1 inhibits the development of mesoderm and ectoderm,as well as promotes the process of apoptosis,nonetheless no change of proliferation is inspected.