According to decades of epidemiological research and experimental studies, there are several possible factors for the occurrence of esophageal cancer as follows: (1) Long-term bad dietary stimulation. Residents in certain areas with high incidence of esophageal cancer are accustomed to consume too hard and rough food for a long time, and chew and swallow quickly when eating; some people also like to drink too hot tea or soup, or too hot porridge. The rough and hard food or overheated food rubs and stimulates the esophageal mucosa, which causes chronic trauma and inflammation of the esophageal mucosa and repeatedly causes the squamous epithelial cells lining the esophagus to be damaged and then proliferate and repair, in which the squamous epithelial cells may become cancerous and produce esophageal cancer. (2) Long-term consumption of water or certain foods with high content of carcinogenic compounds such as amyl nitrite. The higher the intake of such carcinogenic substances, the greater the possibility of esophageal cancer. (3) Long-term chronic inflammation of esophagus. According to the survey, esophageal diverticulum, scar stenosis, chronic esophagitis and esophageal polyp may become malignant and form esophageal cancer if they exist for a long time. (4) Long-term consumption of fermented and moldy food. Epidemiological investigation and animal experimental research confirm that long-term consumption of fermented or moldy food is prone to esophageal cancer due to the presence of many kinds of molds. For example, the content of mold and nitrosamines in food is high, and the two have strong synergistic carcinogenic effects. (5) Long-term smoking and alcohol consumption. Research has found that long-term smokers, especially those who smoke pipe tobacco and chewing tobacco, are not only prone to lung cancer, but also to esophageal cancer, and those who have the habit of drinking alcohol at the same time have a greater risk of esophageal cancer. (6) Genetic factors. The occurrence of esophageal cancer is 80-90% due to acquired factors or environmental factors. However, the survey found that there are also certain genetic factors. (7) Other factors. Investigation and research found that the occurrence of esophageal cancer is related to the lack of certain vitamins and trace elements, such as riboflavin, vitamin C, vitamin A and niacin, and the lack of molybdenum, zinc, selenium and other trace elements. In a word, the occurrence of esophageal cancer is related to the above-mentioned factors, and it is likely to be the result of multiple factors together, but one of them must be the leading factor, and the leading factors leading to esophageal cancer are not the same in different regions and populations.