In the Japan Atomic Energy Research Institute (JAERI), technology for tritium production by use of 6LiAl alloy has been developed with the aim of furnishing tritium for fusion research. The alloy contains β-phase, i.e., intermetallic compound β-LiAl, which has a large influence on the tritium behavior in 6Li-Al alloy. Since β-LiAl has a unique crystal structure and a large amount of Li vacancy at room temperature, the tritium behavior in β-LiAl is affected by the defect structure and the lithium diffusion. In this paper, on the basis of a simultaneous measurement of tritium release rate and electrical reseistivity, it is suggested that the tritium diffusion has a strong correlation with the lithium diffusion in the neutron-irradiated β-6LiAl.