Bivalves is the seashell which is large in quantity and very common to be eaten in Penghu. However, the waste shells often cause environment pollution and trash problems. Recycling and utilization of waste shells would achieve the purpose of reducing waste and reusing of green energy. National and international researches indicate that shell powder has bacteriostatic function. In this study, two kinds of oyster shell powder, unashed and ashed for one hour at 300℃, were used to replace 50% and 100% of coral sand separately inBabylonia areolataaquaculture to evaluate the efficiency of water purification. The results showed that there was no significant difference between each group. Most Babylonia areolata aquaculture in Taiwan use black fine sand as substrate; however, it is detrimental to the growth of Babylonia areolata because that it often causes water to be turbid and contains lots of bacteria. In our center, coral sand had been used to replace black fine sand to enhance the cultivation rate and growth rate; however it became difficult to get because of the prohibition of taking coral sand. Using oyster shell powder to replace black fine sand in Babylonia areolata high density aquaculture could purify water and reduce bacterial contamination as coral sand. If it is able to use waste oyster shell power to replace fine sand and coral sand in Babylonia areolata aquaculture, the cultivation rate would be enhanced and the disease would be reduced.