XDS-3 Inverted biological microscope is equipped excellent UIS optical system including long working distance plan achrom atic objectives and wide field plan eyepieces. Compact and steady main frame body is embodiment for the shock resistance. The enable turning out or into condenser system is suited for observation in a high culture dish. The ideal ergonomic design is adopted in this unit and have easier operation and wider space. This is ideal optical instrument for micro observation in cell tissue and transmitted liquid tissue, even in dynamic observation in the culture dish tissue. It can be used in scientific research, universities, medical treatment, epidemic prevention, agriculture and etc.