Abstract: As a young community of network security research,visualization for network security focuses on taking advantage of the power of the human perceptual and cognitive processes by bringing robust visual tools into hands of humans in solving computer network security problems.Amounts of visual tools have played very significant roles in helping network security analysts to detect anomalies,discover patterns,identify correlations,and assess network security situation.In this paper,we offer a comprehensive review of network security visualization.First,we introduce the necessity and the phased development of this field;then we provide taxonomies from network security visualization technology and visual application in network security;at last we outline some guidelines and directions for future studies.