Computerized tax administration is an important measure of strengthening tax collection and administration. It is also a technical assurance of reducing taxation costs and improving collection and administration effectiveness. With the rapid development of computerized tax administration in China, the information security issue in the tax information construction is becoming a public concern. It has become the bottleneck of China's taxation modernization. Therefore, to solve this problem becomes urgent. This article studies the issue of information security in the tax information construction from three aspects of information state security, information transformation security, and security administration system, and proposes some corresponding strategies on server security, operation system security and database security. Information transformation security strategies on firewall technology, information encrypting technology, information authentication technology and virus prevention technology are put forward. Also is suggested the measures of establishing a set of sound security administration system.