Cities are complex and interdependent systems and they are vulnerable to threats from both natural hazards and terrorism. Features that make cities feasible and desirable, the architectural structure, population concentration, places of assembly and interconnected infrastructure, also put them at high risk to natural hazards and terrorist attack. A recent review of worldwide natural hazard losses during 2001 identified 700 natural disasters, resulting in 25,000 deaths, $36 billion in economic losses, and $11.5 billion in insured losses. Despite of all interests and attentions in the concept of resilient communities, few studies have formulated systematic principles of resilience and applied them at the city scale. At this article has been tried to define vulnerability and resiliency. Then dimensions and components of resiliency of different frameworks and models will be defined.To succeed, this strategy will require changes in national disaster policy, funding for basic and applied urban systems research, support for advanced education programs, and active collaboration among urban planning, design, and construction professions. Finally, the proposed environment resiliency model has been presented by the cause model.