The purpose of this study is to realize features of energy efficiency of desiccant air-conditioning system for dedicated air conditioning system and propose new high efficiency application of dedicated air conditioning systems with desiccant air-conditioner. Many of advanced air conditioning systems, for example, displacement air conditioning system, etc., are intended to reduce energy for only sensitive heat conditioning or space of sensitive heat conditioning. The result show that high efficiency latent heat conditioning system by desiccant air-conditioner combined with these systems bring high efficiency of total air conditioning and advantages against these system with conventional latent heat conditioning systems.