The effects of diluents composition on cold storage for Scapharca broughtonii (Schrenck) sperm were examined in the percentage of sperm activity and survival rate. Various diluents of glucose solutions (10 mM Hepes-pH 7.8), 600 mM NaCl, stein solution, Ringer’s solution(230mM NaCl, 8 mM KCl, 2 mM CaCl2, 3.7 mM MgCl2, 0.2 mM NaHCO3, 10 mM Hepes-pH 7.8), 20%, 25% ASW (NaCl 2.7 g + KCl 0.07 g + CaCl2 0.12 g + MgCl2 0.46 g + NaHCO3 0.05 g + distilled water 100 ml) were used to store th sperm at 4℃. The storage effect was evaluated using sperm activity and survival rate. Ringer's solution was found to be better diluents which maintained high activity and survival rate of sperm for a storage period of 7 days. Optimal pH of diluents to store the sperm at 4℃ is 7.5.