The colleterial gland in the silkworm (Bombyx mori) grew gradually until 2 days before emergence, and markedly enlarged due to the accumulation of glue like substances (mainly including 85% water and 11% proteins). However, the Ng mutant female moth only secreted a small amount of glue-like substance and laid loose eggs naturally. High-resolution two-dimensional polyacrylamide gel electrophoresis, followed by computer-assisted analysis was used to screen the proteins pattern between normal and Ng mutant colleterial gland to find quantitative and qualitative difference in proteins expression. Protein spots were resolved in the secretory region of colleterial gland of silkworm and more than 700 protein spots were resolved and most of the proteins were distributed in the area from 30 ku to 70 ku and pH 4～8. Through the comparison and analysis, it was found that 3 proteins were only expressed in the later pupae stage and moth stage. However, these proeins have no expression in the Ng mutant especially spot No.2 and 3. These differentially expressed proteins were actin identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The results indicated that the actins participate or regulate the exocytosis of colleterial gland and other differential expressed proteins might be having some relations with the glue-like proteins secretion.