First, the scientific significance and economic value of cloning technology. The breakthrough of cloning technology first marks the improvement of human's ability to understand and transform life, which in itself is a great progress of human civilization. As an important achievement of bioengineering, cloning technology provides many possible ways and methods to solve some increasingly acute problems and contradictions. (1) cloning technology has brought a bright application prospect to the medical field. Driven by the human genome, people are carrying out therapeutic cloning experiments, aiming at producing cloned or parthenogenetic human embryos to obtain stem cells, studying difficult diseases such as cancer, AIDS, Alzheimer's disease and Parkinson's disease for human beings, revealing the molecular biological mechanism of diseases from the gene level, predicting the functional and pathological changes of human bodies, and looking for treatment methods to treat both the symptoms and root causes. Cloning bioengineering technology will overcome the disadvantages of Chinese and western medicine and carry out medical revolution in 2 1 century. Therapeutic cloning and stem cell research bring hope for the repair and reconstruction of human missing organs, which can not only treat or prevent organ failure, but also prevent aging and solve the problems of prolonged life and low quality of life we are facing at present. The dream of immortality may come true gradually in 2 1 century. (2) Cloning technology is helpful to accelerate the process of animal and plant breeding. As a major technological breakthrough in the field of biological sciences, cloning technology embodies the progress of nuclear differentiation technology, cell culture and control technology, and provides many possibilities and broad development prospects for saving endangered species. Using somatic cells of excellent animal varieties to provide nuclei for animal cloning can avoid the limitation of animal reproductive cycle and reproductive efficiency under natural conditions, shorten the breeding cycle, improve the breeding efficiency, and create new animal varieties with higher economic value according to their own wishes; It can breed species and protect and save endangered animals. At the same time, cloning technology can transcend the natural rhythm, actively adjust the biological chain and ecological environment, reduce environmental pollution and protect the earth's home. (3) Cloning technology will completely change the pharmaceutical industry and agricultural production. Somatic cloning technology is used to integrate foreign genes into recipient cells and stably transmit them to future generations. It can be used to propagate many valuable genes and directly produce highly effective drugs such as medical protein suitable for human beings. Such as insulin for treating diabetes, growth hormone that is expected to make short patients grow taller again, interferon that can resist infection of many diseases, etc. A new pharmaceutical factory will appear in the cloned goat, producing all kinds of medicinal animals or animal drugs needed for human health. According to calculation, the active protein of human coagulation factor LX provided by a transgenic goat in one year is equivalent to the sum of similar proteins contained in the total blood donation in Shanghai in the whole year. Once people break through the cloning biotechnology, they can change the genotype of crops, cultivate a large number of new varieties with disease resistance, insect resistance, saline-alkali resistance and stable genetic traits in www.shlunwen.com, cultivate excellent animal varieties, and cultivate cows with high milk yield and rich nutrients needed by the human body to meet the nutritional needs of the human body. Second, the negative effects and problems of cloning technology. Science and technology is a double-edged sword, and its role in society is twofold, and cloning technology is no exception. The development of cloning technology is accompanied by the impact on ethics, and its negative impact can not be ignored. Since Dolly was born, the debate about cloning technology has become more and more fierce. The rapid development of cloning technology not only attracted the attention of natural science, but also attracted the attention of social science scientists. Because once this technology is applied to human beings, it will be a severe challenge to human social ethics. Human cloning may have unpredictable negative effects on social morality and social ethics: first, it endangers the principle of harmlessness in ethics. From the example of Dolly sheep, we can see that the success rate of cloning animals is very low, and it may be even lower if it is done on people, and it is likely to produce many deformed and seriously defective clones, which will naturally cause harm to them; Second, human cloning violates the principle of autonomy in ethics. The uniqueness that human cloning enjoys as a human being is rudely deprived; Third, human cloning violates the principle of ethical equality. Human cloning is also a human being, and we can't just regard them as means and tools to serve other people's purposes. People who are negative about cloning technology see a series of social, ethical and legal problems that human cloning may cause. From a political point of view, the emergence of human cloning may threaten human security; From an economic point of view, human cloning may lead to abnormal differentiation of human productive labor, such as making human cloning a slave and tool of human beings; From the perspective of anthropology and sociology, the relationship between clones and donors will be a potential factor of social instability; From a legal point of view, human cloning will create an intractable dilemma for a society ruled by law; From the psychological point of view, human cloning has insurmountable psychological obstacles; From the perspective of evolution, human cloning is not conducive to human evolution; From a philosophical point of view, human cloning destroys human personality and destroys human diversity. Among the social problems that human cloning may cause, the most complicated one is probably the moral and ethical issue. From the perspective of social ethics, the intervention of human cloning in human development will affect the natural composition and development of human beings. The emergence of human cloning will break the traditional reproductive model of combining sex to reproduce offspring, blur human relations, unbalance the sex ratio of the population, and may even be used by people with ulterior motives to create human disasters; From the perspective of family ethics, the application of cloning technology to human reproduction will aggravate the trend of family diversification, fundamentally change human kinship, and the criteria for determining human kinship will also change; From the perspective of sexual ethics, it completely changed the natural fertility model based on sex, separated population production from sex, and destroyed human emotions; From the perspective of bioethics, it destroys people's right to have unique genes, which may lead to the degradation of human race and shake the normal view of life and death.