Well-ordered high crystalline LiNi0.5Mn1.5O4 spinel has been readily synthesized by a molten salt method using a mixture of LiCl and LiOH salts. Synthetic variables on the synthesis of LiNi0.5Mn1.5O4, such as synthetic atmosphere, LiCl salt amount, synthetic temperature, and synthetic time, were intensively investigated. X-ray diffraction (XRD) patterns and scanning electron microscopic (SEM) images showed that LiNi0.5Mn1.5O4 synthesized at 900 and 950°C have cubic spinel structure (Fd 3 ̄ m) with clear octahedral dimension. LiNi0.5Mn1.5O4 spinel phase began to decompose at around 1000°C accompanied with structural and morphological degradation. LiNi0.5Mn1.5O4 powders synthesized at 900°C for 3h delivered an initial discharge capacity of 139mAh/g with excellent capacity retention rate more than 99% after 50 cycles.