A large number of surplus glycerol from the biodiesel production can be used as renewable feedstock to produce glycerol carbonate. In this paper, a series of guanidine-based ionic liquids were synthesized to catalyze the transesterification of glycerol and dimethyl carbonate. The tunable basicity and the anion-cation cooperative effect were responsible for the obtained results. The [TMG][TFE] showed the best activity turnover frequency (TOF) of 1754.0 h(-1), glycerol (GL) conversion of 91.8%, glycerol carbonate (GC) selectivity of 95.5%) at 80 degrees C with 0.1 mol% catalyst for 30 min. The reaction mechanism of the transesterification was also proposed. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.