Aerosol is one of the most uncertain factors in climate change study, and more observation and research worldwide pay much attention to its climate effect. There are two worldwide aerosol observation nets, one is WMO/GAW, and the other is AERONET. Some features about their organization, size, equipment, data, calibration and standards are introduced. Furthermore, some important aerosol scientific plans are introduced with their scientific objects, approach, measurements, and their dependence on aerosol observation net. In addition, the construction of China aerosol net (CAeroNet) is introduced and compared with other aerosol nets. Chinese Meteorological Administration builds CAeroNet, 20 observation sites over northern China, in order to monitor the dust storm and answer the climate effect of Asian aerosol. Through the ongoing Chinese aerosol science plans proposed by Chinese meteorological administration and national nature science foundation of China (NSFC), CAeroNet will play an important role in Chinese aerosol science research.