The protective effect of Sialoglycoproteins of Carassius auratus eggs (Ca-SGP) on bone loss was examined. The animal model was established by male senescence-accelerated mouse. The mice were intragastric administrated daily with Ca-SGP for 150 days. At the end of the experiment, the bone metabolic indexes, mineral apposition rate (MAR) of femoral, bone mineral density (BMD) and trabecular microstructure of tibia were measured. Results indicated that Ca-SGP (500mg/kg?bw) rescued the decreased bone formation by significantly increasing the activity of bone alkaline phosphatase, propeptide carboxy-terminal procollagen and osteocalein levels in serum (P<0.01). Moreover, it inhibited the over-active bone resorption as evidenced by extremely decreasing the activities of tartrate resistant acid and cathepsin K (P<0.01). Meanwhile, tibial BMD was drastically increased by 10.92% (P<0.01). Ca-SGP enhanced trabecular bone microstructure including bone mass, trabecular number, trabecular thickness, and trabecular separation. In addition, Ca-SGP promoted new bone formation and markedly increased MAR by 98.87% (P<0.01). These results demonstrated that Ca-SGP exhibited ameliorative effect on low bone turnover in aged males with osteoporosis, enhanced their BMD, trabecular microstructure and bone mineralization, which may provide some theoretical basis for the utilization of Ca-SGP as an anti-osteoporotic agent or functional food.