According to the record, the types of Sea Urchin that can be seen very often in Taiwan are 16 types, and only the sea area of Baisha Township includes 11 types. Among them, it is Urchin with white thorn bush commonly named “horse excrement urchin” which has the highest economic value. Now it has become a high-class meal in Penghu food and beverage industry. This sea urchin lives on coral zones or reef zones, eating algae and seaweed as food. Its reproduction gland is full of body cavities during reproduction season, making it plump and pretty and the catching target of divers. It not only makes horse excrement urchin having a worry of extinction, but also represents the disappearance of herbivore in the coral reel ecology. That will cause a big amount of algae reproduction and the competition among coral communities, so that change the whole coral ecosystem. Therefore, the excess of catching should be limited to keep the ecological balance.