A carbamate organocatalyst (TEPA-EC) for the synthesis of methyl ethyl carbonate (EMC) was synthesized by the addition reaction between tetraethylenepentamine (TEPA) and ethylene carbonate (EC). The structure of TEPA-EC was characterized by FTIR and NMR, and the catalytic mechanism was analyzed. The effects of synthesis and application conditions of TEPA-EC were investigated on its catalytic activity and transesterification efficiency, respectively. The stability and water resistance of TEPA-EC were also assessed. The results shows that the hydroxyethyl tert-aminoformate group of TEPA-EC can facilitate the transesterification between dimethyl carbonate (DMC) and ethyl alcohol (EtOH) via synergistic hydrogen-bonding. The TEPA-EC catalyst of high catalytic activity can be obtained when EC reacts with TEPA at 140℃ for 2 hours by a molar ratio of 5∶1. When DMC reacts with EtOH by a molar ratio of 2∶1 at 78℃ for 7 hours and the amount of TEPA-EC accounts for 1% of the total mass of raw materials, the conversion of EtOH and selectivity of EMC are 59.50% and 83.77% respectively. The catalytic efficiency of TEPA-EC is comparable to that of sodium ethoxide used in industrial applications. For the transesterification under the same conditions as above, the conversion of EtOH and selectivity of EMC fluctuate around 62.35%, 86.03% and 57.33%, 87.91% respectively during 8 times of repeated use and 14 times of circulated use with water, when the amount of TEPA-EC catalyst is 3% of the total mass of raw material. TEPA-EC shows much better stability and water resistance than sodium ethoxide.