The study on bio-electromagnetics can be traced back to as early as 1789, The understanding of its nature and application has been increasing with technological development studies at home and abroad. It has been suggested that electromagnetic radiation can induce different injury to human organs including central nervous system, incretion, cardiovascular system, procreation, hematopoietic system, immunity, vision and so on. However, the studied results obtained by scientists with different method and bio-model show very complex and some show inconsistent. This paper is to summarize the studies of effects on various organs by microwave.