Aimed at the defects of security monitoring system in intelligent building with complicated design, higher production cost, uneasy to installation, and not suitable for ordinary family, this paper combined with the development needs of intelligent building, and designed a remote network security monitoring system based on Internet, used AT91SAM9260 as the main controller and used embedded technology, Internet technology, video compression/decompression technology and so on. So that users can detect the illegal intrusion and fire hazards at home in real-time, through computers or mobile phones. Then the validity and efficiency of the system was validated via test-experiment. The results show that this system has several merits such as good safety, good generality, simple operation, easy maintenance, low cost and so on. It can meet the needs of security monitoring for an ordinary home.