The invention provides an application and promotion system based on network agent, wherein the system comprises a network agent module, used for sending invitation code to the user, monitoring the channel user for downloading the resource, returning the request data status code to many application modules, having statistic analysis on monitoring data reported by the many application modules, having statistics on the number of channel user according to the invitation code, the contribution value of each developmental channel user and calculating the royalty income; a plurality of installed assistant modules coupled to the network agent module and used for installing the application modules to the mobile phone terminal for the channel user, collecting the monitoring data reported by the application modules, sending the monitoring data to the network agent module; a plurality of application modules. The installed assistant modules creates earnings for the installed assistant platform and network agent marketing user, the cost is low and the reward is high, the propagation mode is high effective and fast and the application sharing mechanism is raised.