Abstract: The feasibility of planning and constructing PKI/CA certification system in the tobacco industry was analyzed, it was concluded that PKI/CA certification was an infrastructure to ensure the security of electronic business affairs, electronic government affairs and other information systems of the tobacco industry.The PKI/CA certification technology was introduced, and the 3 major existing construction modes were analyzed.Combining the practice of system application and characteristics of the tobacco industry, the PKI/CA system of the tobacco industry should be specially designed completely and be multilevel in structure.The major problems existing in planning, implementing and popularizing were also discussed.