The increase in crop yield,the improvement of product quality,and the reduction of losses are directly related to the availability of energy.Fossil fuels that have to be imported,whenever they are available,by most developing countries,are expensive in rural areas.Therefore providing energy from altemative sources is an urgent necessity.For these purposes a new solar dryer with air circulation system for pharmaceutical plants was constructed.Region the solar radiation and meteorological data of mashhad (a city in Iran) along with psychometric chart were used in calculation.For circulating the air in the dryer,a small fan working with the city electrical outlet was used.Heating the air was accomplished using a flat plate solar collector with a net area of 1.48 m2.The double glazing cover plate was used to reduce the heat loss and to increase the overall efficiency of the collector.The drying chamber had three trays with dimensions of 0.51*0.88 m2.