1. microprocessor controller for temperature and humidity ensures a stable and precise control. 2. temperature-setting function makes the temperature of day and night changed differently with the light alternated from on to off. 3. independent alarm system for temperature-limiting ensures experiments run safely and no accident would happen. 4. particular circulating system of air ducts ensures wind distribute evenly in chamber,which prevents plant seedlings from blowing. 5. specular stainless-steel chamber and semicircular arcs at corners ensures an easy cleaning. 6. main parts such as compressor and circulating fan are imported for reliability and safety. 7. microcomputer interface is an option,which can scout process of experiment.(option)