Recently, the rapid decrease of animals has drawn the attention of the whole society. It seems to be an inevitable result of the development of human society. However, protecting animals, as far as I am concerned, is still extremely important for their irreplaceable value on science and environment. As is known to all, wild animals are playing important roles in scientific research. It is reported in “science” last year that about 5 million wild animals are used by scientists to make science researches on life process, environment, medicine and many other fields. Moreover, researchers also do experiments on animals before doing them on human in consideration of the security. It is undoubted that without the sacrifice of numerous animals, science and technology won’t develop in this magical speed. Besides, the balance of nature requests the effort of both human and animal. Without animals, human’s survival will become extremely difficult and our society will stop developing or even step back. Similarly, without human, animals can hardly survive these terrible disasters. For instance, dinosaurs were extinct millions of years ago because they did not have a brain like human which could help them avoid dying. In conclusion, despite of the lack of resources, we should exert ourselves to protect and cherish these lovely wild animals for the mutual dependence of both parts. Much as it costs, it is still worth investing in that it will not only accelerate the development of science and technology, but also contribute to the establishment of a harmonious