Abstract: The proteins during earlier stages of embryo (before the head thorax differentiation  embryo) and their changes were analyzed using silkworm Bombyx mori variety P50 as experimental material by two dimensional polyacrylamide gel electrophoresis and image analysis system to analyze the change of total proteins from silkworm embryo. It was discovered that two dimensional polyacrylamide gel electrophoresis patterns of protein from the critical development Ⅱ  stage embryo to the shortening  stage embryo stayed basically stable, and only a small number of the protein spots existed in the critical development Ⅱ  stage embryo disappeared at four earlier embryo stages of incubation, which only accounted for 22.80％, but the protein spots which disappeared at 2 last embryos of incubation accounted for 48.18％; 100 different protein spots from the neural groove appearance, abdominal outgrowth appearance, labrum appearance and shortening stage embryo can be detected and most of these protein spots disappeared in the embryos closely followed. The results suggested these different proteins might relate to the characteristics of corresponding embryo body development.

Key words: Bombyx mori;protein, two dimensional electrophoresis, image analysis, embryo development