In China, we do not attach much importance to the theory of the solar drying research in the early stage, have superficial understandings on the principle of the solar drying and lack systematic basic research, especially conduct little research on the dryer. So, both drying equipments and systems are not perfect and the experimental study still undergoes repeated experiments on the low level state. With the progress of the technology in China, scientific and research talents spring up. They have deeper and more systematic theoretical research on the solar drying and establish and deduce many mathematical models, features of which are as follows: ķestablish the performance test and evaluation indexes of the dryer. Conduct optimized design on the solar drying process and parameters, improve the performance of the dryer and the thermal efficiency of the dryer with these indexes; ĸestablish the solar drying theoretical mathematical models. Summarize up major drying parameters as well as study the relationship among various parameters and build mathematical models by the experimental research of features of the materials drying process, so as to lay a foundation for the realization of the computer simulation of the solar drying process; Ĺwith larger research area and scope and strong academic atmosphere. At present, the area the solar drying involves in is larger. Where there is drying area, there are researchers conducting research on the theories and experiments. Contents of the research are wider, at the same time, communications between researchers