Early development of Xenopus laevis embryos was investigated. Staging of embryo agreed well with the previous data, generaly. Staging of individual embryo, however, varied from embryo to embryo and variety of staging was also seen among the embryos from different parents. The profile of increase in the number of cell with development from firtelized egg to early gastrula stage was the same as that of described before but that of later stage was not. Finally,effects of temperature on the development were analyzed, and it was shown that there was significant difference in development between ages of embryos at 4 ℃.