Abstract: Sialoglycoprotein was extracted from eggs of Carassius auratus,and its immunomodulatory effects on immunocompromized mice were studied. Different dosage of sialoglycoprotein from eggs of Carassius auratus was given to immunodepressive model mice induced by Hydrocortisone for 28 d. The antibody level,immunological function of T cell and level of serum interferon- γ( IFN- γ) and interleukin- 4( IL- 4) was measured. Results showed that high-dose of sialoglycoprotein could increased the hemolysin content and numbers of antibody-forming cells(p<0.01) and strengthened lymphocyte proliferation(p<0.01) significantly. It could aslo increase toe incrassation(p<0.01) and promote phagocytosis ability of celiac macrophage(p<0.05)and serum IFN-γ/IL-4(p<0.01) markedly. Data suggested that the sialoglycoprotein from Carassius auratus had significant immunomodulatory effects on immunocompromized mice.