Abstract: In order to understand the contribution of lightning to the abundance of NO_x in the upper troposphere, the characteristics of spatial and temporal distribution of NO_x in the upper troposphere and lightning in China, and the relationships between them are analyzed in this paper. The lightning data (from April 1995 to December 2005) and the NO_x data (from October 1991 to November 2005) are obtained from the Global Hydrology Resource Center (GHRC), USA and the Halogen Occultation Experiment (HALOE) boarded on the Upper Atmosphere Research Satellite (UARS), respectively. It is found that lightning activities are in very good agreement with NO_x volume mixing ratio in seasonal variations, annual variations, and spatial variations. The results prove that lightning is an important source of NO_x in the upper troposphere. The height of the extreme value of NO is at about 350 hPa, while that of NO₂ is at about 250 hPa. Intra-cloud lightning-generated NO is the main reason for the extreme value, the NO will oxidize into NO₂ during the transmission process, and NO₂ will be transported to higher height through the thunderstorms. Strong convective is helpful to transport NO_x to the upper troposphere, while NO_x generated by human activities can hardly do this. Therefore, in the area that more lightnings occur, the extreme value is bigger and its height is higher.