The virtual line fence security detection software function can detect the image taken by the camera, and setting the virtual protection line through the software algorithm operation under camera visible area. The virtual protection line can be set in the monitoring safety area, and body can cross the virtual line according to the setting Of the direction of the different, to detect. And by the intelligent surveillance system (huperVision 4000), automatically activate the alarm system and notify the administrator. This recognition detection software was included in huperVision 4000 system software as standard function software.