Malignant tumors have become the main cause of death for residents in China, accounting for more than 20% of the causes of death. In 2006, the statistics of causes of death in 30 cities and 78 rural counties in China showed that compared with 2005, the mortality rate of malignant tumors in urban and rural residents increased by 18.6% and 23.1% respectively, which is a very alarming growth rate. At the same time, China’s cancer spectrum has also undergone major changes, breast cancer and colorectal cancer have jumped to the top ten of malignant tumor incidence, the incidence of pancreatic cancer and kidney cancer has increased significantly; the incidence of stomach cancer and liver cancer is still high. In the past 20 years, among the top 10 malignant tumors in men, lung cancer, kidney cancer, colorectal cancer and brain tumor are on the rise, among which kidney cancer has the largest increase, with a cumulative increase of 111.72%. Among the top ten malignant tumors in women, the incidence of pancreatic cancer, breast cancer, lung cancer and ovarian cancer are on the rise, with pancreatic cancer showing the greatest increase; cervical cancer, esophageal cancer, stomach cancer and liver cancer are on the decline, with cervical cancer showing the greatest decline. However, in recent years, in some areas, the incidence of cervical cancer among young people has also shown an increasing trend, which deserves attention. Although the incidence rate of some tumors has decreased, the overall incidence rate of tumors in China will still continue to go high. Now, lung cancer still ranks as the number one cancer killer in China, and female breast cancer is growing rapidly and will become the number one killer threatening women’s health in China, followed by lung cancer, colorectal cancer, liver cancer and ovarian cancer. Etiology prevention is one of the most important methods to reduce the incidence rate, that is, to determine the risk factors affecting the occurrence of malignant tumors and to find susceptible people. The change of tumor incidence is mainly influenced by various factors such as age structure of population, nutrition, genetics, environment, lifestyle and economic level, education level, etc. Among them, smoking, obesity, diabetes, viral infection, unhealthy diet are the first and foremost causes. It can be seen that tumor is a kind of lifestyle disease. As long as the bad habits are eliminated, cancer can be completely kept out of the door. According to Prof. Deng Xiaohong, deputy director of Beijing Municipal Health Bureau: In 2007, there were 66,421 deaths among Beijing residents, with a mortality rate of 5.51‰. The cause of death is still mainly chronic non-communicable diseases, the top five are malignant tumors, cerebrovascular diseases, heart disease, respiratory diseases and injury poisoning, accounting for 86.58% of the total number of deaths. The proportion of deaths from infectious diseases is very low, accounting for only 0.91% of total deaths, with the highest number of deaths from viral hepatitis and tuberculosis. Compared with 2006, there were some changes in the top ten causes of death last year. Among them, malignant tumors rose from the third place to the first place, accounting for 24.55% of the total number of deaths in the city last year, and mainly lung cancer, liver cancer, intestinal cancer; cerebrovascular disease from the first place in 2006 to the second place, heart disease deaths from the second place in 2006 to the third place. Among the malignant tumor deaths, lung cancer ranked first for both men and women. In addition, the total mortality rate in 2007 was 5.34‰ in urban areas and 5.90‰ in suburban counties, which was slightly higher in suburban counties. The first cause of death in urban areas is malignant tumor, and the first cause of death in suburban counties is cerebrovascular disease. The composition of tumor morbidity and mortality of urban and rural residents in China is changing, and the mortality rate of some malignant tumors has significantly decreased, and the composition of tumors is increasingly tending to the tumor mortality pattern of developed countries. The trend of malignant tumor changes in China has three characteristics: 1. 2. The mortality rate and its composition of lung cancer, liver cancer, colorectal cancer, breast cancer and bladder cancer, which are related to the environment and lifestyle, are on the rise, among which lung cancer and breast cancer have increased the most, by 465% and 96% respectively in the past 30 years. 3. From the composition of the top ten malignant tumors in urban and rural areas, lung cancer has replaced liver cancer as the first cause of death from malignant tumors in China (accounting for 22.7% of all deaths from malignant tumors). Comparing the composition of urban and rural tumors in China, especially in urban areas, the trend of change is similar to that of developed countries.