A research finds that everyday there is a kind of animal extinctive on the earth. If we multiple it with a year time, we will say goodbye to more than 300 kinds of animals every year. How terriorable it is! However it is the truth. So for our descendents can also see some animals not only in the zoos, we should do soothing to save the disappearing friends.As we know, animals have a huge worthy of medical use. For instance, the tiger's bone is good for our healthy, so there are a lot of people kill tigers and sell them for money.Besides this, the idea of some useful inventions of human is coming from animal. The most famous example is the reda, which is based on the echolocation system of  bats. With the help of it, we can detect some planes from other countries in order to make sure the safe of our homeland.The variety of animals is also important to the balance of ecosystem. If one point of the ecological chain is lost, their preys will increased immedirately, but their predators will decrease on the contary. Then the region may meet some disasters, as the farmland is full of bad insects because of the died of birds feed on them. This may directly influence the food it produce, and the economic loss is even worse.Even though our country have already made some laws to protect some precious animals, and the people who kill and sell these animals have to receive the punishment, losing their money, freedom, and even life. But this is not enough to prevent the animals from disappearing. Everybody should keep in mind that we should protect animals, and they are our best friends. Then we can take part in the associations organized by government or even NGO to do what we can do, adoring money for construction of protect region for special species, telling others the importance of protecting animals, and so on. Any one of us is small, but our group is strong enough to save the poor animals who are still love life.