Amorphous transition metal polysulfides are promising high capacity electrode active materials for sodium secondary batteries. Here we report the superior electrode performance of amorphous Na2TiS3. Crystalline (c-) and amorphous (a-) Na2TiS3 were prepared by solid phase reaction with heat treatment and mechanochemical reaction, respectively. a-Na2TiS3 showed 10 fold higher ionic conductivity (1.5 x 10(-6) S cm(-1)) than that of c-Na2TiS3. The all-solid-state cells using c-Na2TiS3 and a-Na2TiS3 showed reversible capacities of 110 mAhg(-1) and 250 mAhg(-1), respectively. Amorphization of Na2TiS3 is a powerful way to improve electrode performance in all-solid-state sodium secondary batteries.