The International Union Against Cancer believes that one third of malignant tumors can be prevented, one third of malignant tumors can be cured if they are diagnosed early, and the other third of malignant tumors can improve their quality of life through reasonable treatment, especially the psychological treatment of patients in the middle and late stages. Zhang Feng, Oncology Center of Shandong Chest Hospital Prevention and early diagnosis of tumor is the most fundamental and effective way to solve the tumor problem at present. Traditional clinical diagnosis has no effective means to detect early tumors. With the development of molecular biology, the technology and methods of molecular diagnosis through genetic testing make the early screening and diagnosis of tumor possible. 1.Tumor marker detection: tumor markers are directly related to the occurrence of tumor, and tumor judgment is made before the conventional physical examination, so as to fight for the earliest treatment time for possible tumor patients. 2.Molecular diagnosis of tumor in early stage: to find the small changes of tumor occurrence from the most fundamental nucleic acid mutation genes, to make tumor early warning in the first time, to find tumor patients in earlier stage than traditional sense, and then to prevent tumor occurrence or to cure tumor by targeted examination or through early tumor treatment methods. 3. Molecular diagnosis of tumor susceptibility: assess the risk of tumor disease from genetic information and provide the most long-term report of tumor prevention. Through lifestyle intervention or appropriate drug intervention, the risk of tumor disease can be significantly reduced and the occurrence of tumor can be prevented. At present, China is building a tumor early treatment center, through tumor marker detection, tumor early molecular diagnosis, tumor susceptibility molecular diagnosis, so that the early screening, diagnosis and treatment of tumor can become a more perfect system, thus significantly reducing the incidence of tumor and reducing the mortality of tumor.