Tritium is a fuel and the most mobile and significant radioactive sources for ITER. In the design of TBM tritium systems of China, the safety design of common chemistry engineering system and tritium safety design are considered at the same time. It is necessary to avoid a continuous increase of the tritium concentration in the coolant and to reduce the tritium permeation into the secondary coolant as well as environment. In this paper, the design and tritium permeation analysis of China HCCB TBM port cell are introduced. At first, the primary design considerations of the system are given to fulfill the engineering demand of the ordinary system (non radioactive system). Then the tritium permeation, the release analysis, the effect of tritium release to the people and environment are discussed. From the calculation of the tritium permeation in the systems housed in the port cell, tritium permeation barrier is needed in the higher temperature components such as the reduction bed and the heater.