The effect of microinjected gene on embryonic development showed differences depending on the concentration, the incubation temperature and the injection site. In order to study the effect of exogenous DNA concentrations on embryonic development, various concentrations of Bag DNA (cytoplasmic actin promoter is linked to β-galactosidase gene) were microinjected into fertilized Xenopus eggs. It turned out to be that Microinjection of 1-2 ng DNA dissolved in 20 nl TE buffer was not shown to disturb normal embryonic development, and recorded the highest survivability to late tadpole stage (stage 43); however, injection of increasing concentrations of DNA provoked irregular cleavages, which resulted in reduced survivability. When the injected embryos were incubated at low temperature (e.g., 12℃), over 50% of embryos developed to tadpole stage; whereas, less than 45% survived when incubated at room temperature. A possible explanation for this phenomenon is that at low temperature, where embryonic development is slower than at room temperature, the normal cell cycle is delayed; therefore, wider the exogenous DNA diffuses into balstomeres, less toxic effects does it have on embryonic development. The survivability also showed differences according to the injection site. Over 60% of embryos developed to stage 43 when microinjected into vegetal hemisphere, whereas lower than 50% survived when microinjected into animal hemisphere. As well, the wider expression of β-gal was observed on vegetal hemisphere than animal hemisphere. These findings strongly suggest that the injection site is closely related to the expression pattern of microinjected gene as well as survivability.