Acceptor-doped perovskite oxides exhibit significant proton conductivity under humid or hydrogen containing atmosphere, which opens a unique possibility to be used as electrolyte material for fuel cell. A challenge facing by many material scientists is to develop electrolyte materials with very high proton conductivity. In this proposal, we propose to carry out an in-situ neutron diffraction experiment of dried BaZr0.5In0.5O3-d sample under humid (D2O+Ar) atmosphere at different temperatures (ambient -1000°C). This in-situ study will provide us with a deeper understanding of proton transport (both kinetics and dynamics) in the bulk material.