Abstract: A molecular-thermodynamic model is established for predicting VLE (see title) inamine-promoted carbonate solutions between 343. 15 K and 403. 15 K in the range of con-centrations encountered in gas treating process. The model is based upon the work byChen et al. (1979) on VLE of aqueous electrolyte systems with molecular solutes, andextends its validity by applying Edwards' idea (1978) and mechanism of CO_2 rate promo-tion in carbonate solutions. The simple program SUYZ 1 with flexible functions of doing a series of calculationshas been developed. It can be used either predicting VLE or optimizing the adjustableparameters. For the system of K_2CO_3-CO_2-H_2O-DEA, good prediction of VLE data isachieved. Besides, correlations of VLE data were carried out for the K_2CO_3-CO_2-H_2Osystem studied by Tosh et al. (1959) with tempratures from 343. 15 K to 403. 15 K andconcentrations up to 40 weight percent equivalent potassium carbonate. To test the validity of the model, a static experimental apparatus has been used tomeasure VLE data for the K_2CO_3-CO_2-H_2O-DEA system. The success of the predictionsuggests the validity of the model for amine-promoted carbonate solutions of industrialinterest.