Beryllium alloys such as Be-Ti and Be-V have been proposed as candidates for advanced neutron multipliers because of their high melting point, high beryllium content, low activation, good chemical stability, etc. In this study, compatibility tests between Be-Ti and structural material were performed, and the effect of Ti content on compatibility was evaluated. Four kinds of Be-Ti alloys (Ti content: 3 to 8.5 at. %) were used in the compatibility tests. After annealing of each Be-Ti alloy in contact with Type 316LN stainless steel (SS316LN), depletion of αBe was observed by electron probe microanalysis on the Be-Ti side after annealing at 800°C for 1000 h, but the reaction products were not observed on the Be-Ti side. Reaction products such as BeNi and Be 2 Fe were observed on the surface of SS316LN. The thickness and growth rate of the reaction layer on the SS316LN side decreased with increasing Ti content in the Be-Ti alloys.