A series of amines are applied as catalysts in the aminolysis reactions of five‐membered cyclic carbonate (5CC). Kinetic results display that TBD, which has a guanidine structure, exhibits the best catalytic efficacy and the reaction rate constant is about 100 times higher than the blank system without catalyst. The reaction medium, NMP is found to be as both solvent and promoter in the aminolysis of 5CC. Finally, with TBD and NMP as catalyst and solvent, respectively, the polymerization of bis‐functional 5CC (B5CC) and 1, 6‐diaminohexane can proceed almost 100% at room temperature in less than 4 h to obtain poly(hydroxyurethane)s (PHUs) with moderate molecular weight.