Two different solar desiccant-dehumidification-regeneration systems have been studied. Both have the same glazed area and utilize similar mechanisms for dehumidification and regeneration. The solid desiccant used is silica gel and the particle sizes fall in the ranges of 6-8 and 2-4 mesh. The structures of the systems are simple and they are suitable for such applications as air-conditioning, drying, dehydration, and active cooling. The only energy used is from ventilating fans and solar energy input for system regeneration. There is a large potential for dehumidification in Taiwan.