Abstract: The extraction process of nucleoprotein and protamine from freshwater fish spermary was studied.The extraction conditions were optimized by using the orthogonal design.In extracting nucleoprotein,NaCl concentration was 1.0mol/L,the volume of NaCl solution was ten times as large as that of fish spermary,extraction time was 1 hour,the volume of 95% alcohol solution was two times as large as that of fish spermary.In extracting protamine,H2SO4 concentration was 5.0%,the volume of H2SO4 and 95% alcohol solution were three times as large as those of fish spermary,extraction time was two hours.

Key words: Freshwater fish spermary Nucleoprotein protamine The conditions of extraction technology