Abstract: China, a great country with tremendous scientific research achievements, meanwhile, is also a country which has the serious problem of the great outflow of the scientific research achievements. Based on the results of the two databases (EI and web of science), as well as the recent ten years data sampled, here we analyze the quantity, the quality, and the disciplines covered by our outflow research papers, in addition, we present the detailed observations of the harm brought about by the outflow of the scientific research, the economy development, and the information security. Two primary reasons that result in outflow of scientific research are found, one is deviation and alienation of the domestic appraisal system and guidance, and another is the influence and appeal of science and technology journals published by developed countries. The paper provides a thorough analysis of the chronic problems in domestic appraisal system and great disparity between domestic journals and overseas journals. On the above basis, it suggests the specific measures to prevent the outflow of scientific research papers such as creating suitable cultural environment for scientific research, establishment of a scientific academic appraisal system to arouse researchers to devote to science research, focusing on development of domestic database of English academic periodicals and index to keep pace with the world.