Ba3(Ca1.18Nb1.82)O9-δ (BCN18) is a novel complex perovskite structure proton conductor. Nanocrystalline BCN18 was synthesized by means of sol-gel method. The solid oxide electrolyte was prepared by using this powder, and its sintering behavior was studied. SEM and XRD were performed to demonstrate its sintering properties. Its electrical conductivity was systematically investigated at intermediate temperature (400～600°C).