There are two most important technologies in this century, one is biomedicine and the other is energy technology. Energy issue produced problems or adverse effects in different levels of industry or in living. The Global warming also arouse the awareness of the public in energy saving. Therefore new energy saving technologies are appearing and developing rapidly, at the same time energy regeneration or alternative technology are developing in large scale. Basically energy problem can be classified into the following 3 solutions in general: energy saving, energy searching and energy recycling. Energy saving is an important item among the concept of environmental protection, economy and improved science and technology. This paper discusses various energy saving systems and technologies and analyzes energy saving products in order that the public understands saving methods. This paper concentrates on energy saving devices.