In International Fusion Material Irradiation Facility (IFMIF), neutrons are produced by the reaction between 40 MeV deuterium and liquid lithium. In this process, tritium (3 × 1011 Bq/h) is generated in the lithium flow. Tritium permeation and inventory of IFMIF lithium loop components are evaluated for safety of the IFMIF and the design of tritium processing system of the IFMIF. The tritium permeation rate from a V-Ti hot trap is about 95% of the total amount, 1.0 × 106 Bq/h, from lithium loop. Therefore, the reduction of the tritium permeation rate from only the V-Ti hot trap can directly reduce the total tritium permeation from the Li loop and the gaseous tritium in the Li loop area. Total tritium contained in the walls ewt by liquid lithium in the IFMIF is 5.3 × 107 Bq, which is much smaller than 4.9 × 1014 Bq of tritium contained in the Li flow with a volume of 9 m3.