Abstract The NaOH/γ-Al2O3 as catalyst for the synthesis of glycerol carbonate via transesterification of glycerol with dimethyl carbonate (DMC) has been developed in this work. It was found that NaOH/γ-Al2O3 was a highly efficient heterogeneous catalyst for the synthesis of glycerol carbonate and the catalyst can be easily recovered and recycled. Under the conditions of DMC/glycerol molar ratio of 2, catalyst/glycerol weight ratio of 3%, reaction time of 1 h, and reaction temperature of 78 °C, the conversion of glycerol and the selectivity to glycerol carbonate reached 97.9% and 99.0%, respectively. The catalytic performance of 80 wt.% NaOH/γ-Al2O3 is much better than that of K2CO3. A plausible reaction mechanism about this catalytic reaction was also proposed.