The warming trend of the global climate system continues, and the impact on natural ecosystems and water resources continues to rise, aggravating the already fragile global water resources. At this background, as a potential water resource, non-precipitation water (NPW) in arid area plays an important role in the maintenance of ecosystem and land surface water balance in arid area. Therefore, based on the present results of international research on NPW, the development process of NPW is summarized. The observation methods, variation characteristics, formation mechanism and the contribution of NPW to land surface water balance and its effects on crops in arid areas of Northwest China were reviewed. Finally, on the basis of combining the international frontiers, hot issues and development trends of NPW research, the shortcomings and problems of current NPW research are analyzed scientifically. It is pointed out that the study of NPW should focus on further revealing the complex formation mechanism of NPW on land surface, and strengthen the cognition of NPW in different climatic regions and different underlying surfaces. Breakthroughs have been made in key scientific issues such as the establishment of a specially targeted land surface NPW observation system, the development of the parameterization of land surface NPW in the numerical model, and the research and development of technical standards for the development and utilizationof land surface NPW.
