Most of the systematic studies on affecting photoluminescence (PL) properties in single-crystal perovskite (MAPbX3: MA = CH3NH3, X = Br, I) have focused on changing the compositions of inorganic content. Here, a serious of MAPbX3 perovskite single crystals with different molar ratio of organic to inorganic were successfully prepared by inverse temperature crystallization (ITC) method. The morphology and the PL properties of the single crystals with different ratios of organic to inorganic content were investigated. We demonstrated that the PL intensity of MAPbX3 was increased with increasing the organic content of the perovskite single crystals. It was found that morphology and lattice constants of the perovskite crystals were varied with changing of the organic content. The mechanism of the effect of organic content on optical properties of single-crystal perovskite was discussed.