Diffusion of adsorbed deuterium in Ti-D compound has been studied.Theconcentration of deuterium both in the internal and at the surface of titanium afterdecomposing titanium deutride at an annealing temperature of 343oC were measuredby ’He--D forword recoil detection.From the obtained data and diffusion equations

the diffusion coefficient of deuteriu!n in titanium and the surface recombinationcoefficient were deduced.These coefficients are compared with that for the implanteddeuterium in titanium.