Abstract:Concha Osterae (the shell of Ostera gigas) ignited under different conditions was compared and discussed in terms of appearance features, yeilding ratio of ignited product, Ca content of the ignited product, decocting rate of total component, Ca2+ content of decoction and trace element content. Furthermore, calcined Concha Osterae products obtained commercially from 6 cities of China were also compared in regard to the quality.