The invention discloses a warning video network storage method for a video monitoring system, which includes the following steps that: users configure warning video parameters on a configuration manager; a monitoring front-end reports a warning incident to the configuration manager when the warning incident is detected, the configuration manager sends a warning video command to a media server, the media server receives monitoring data from a monitoring front-end and writes it into a storage device, when the configuration manager sends a stop-videoing command, the media server stops receiving monitoring data and writing it into the storage device, and a warning video is generated. The invention also discloses a video monitoring system. The invention realizes the network storage for the front-end warning video of a carrier-class monitoring system on the media server, which effectively enhances the reliability and usability of monitoring video, provides a strong basis for alarm retrospective analysis, and obviously reduces the pre-investment of operators and the maintenance cost of system.