Desiccant cooling is efficient in latent cooling, whereas chilled-ceiling is efficient for sensible cooling. In this paper, a new desiccant cooling system, a pre-cooling Munters environmental control (PMEC) cycle is proposed, which combines with chilled-ceiling panels. The mathematical model of the system is provided and used to predict the system performance under South-east China weather conditions using hour-by-hour calculations. The results indicate that chilled-ceiling combined with desiccant cooling could save up to 40% of primary energy consumption, in comparison with a conventional constant volume all-air system. More interestingly, more than 99% of annual operating hours for desiccant regeneration could be accomplished by low-grade heat of less than 80 degreesC with the new cycle, while 30% annual operating hours need heat higher than 80 degreesC with the old MEC cycle.