Abstract: In order to investigate the effects of different drying processes on properties of heat pump system for curing tobacco, the application performance of a novel heat pump system for tobacco leaf flue-curing was analyzed and compared based on isenthalpic and isothermal process. On the basis of given system design parameters and tobacco curing process, the maximum heat load in barn was 37.05 kW both during isenthalpic and isothermal processes when the quantity of fresh tobacco loaded was 3 000 kg. The coefficient of performance (COP) during isothermal process was higher than that during isenthalpic process throughout the periods of curing tobacco. The average specific moisture extraction rate (SMER) throughout isothermal process was 0.13 kg/(kW·h) higher than that throughout isenthalpic process. Moreover it could be concluded that the curing cost with heat pump system in isothermal processes was reduced 0.06 Yuan per 1 kg dry tobacco leaves than that in isenthalpic process, totally saving 28.86 Yuan by 481 kg dry tobacco leaves. Therefore, the heat pump system for tobacco leaf flue-curing in isothermal process has better performance than those in isenthalpic process.