In the process of promoting the modernization of national governance system and governance capacity，informatization has become an important tool and provides technical support，which exhibits the characteristics of digitalization，networking and intelligence. The leading role of informatization in the overall modernization construction has become increasingly prominent，mainly manifested in：（1） improving institutional system，promoting the innovation of institutional mechanisms，organizational structure，business processes and other changes，and accelerating the modernization of governance system；（2） enhancing governance capacity，achieving more scientific decision-making，more effective supervision and management，more responsive services，promoting the modernization of governance capacity. This paper analyses the contribution of informatization to the modernization of national governance in general，and then focuses on the role of informatization in various fields by targeting the overall plan for promoting economic，political，cultural，social and ecological progress，and points out the main existing problems.