Abstract: In order to satisfy the high-level user requirements from tasks,this paper analyzes the availability,dependence and capability(ADC) by considering five factors,i.e.,object,task,condition,time and ability,and proposes an ADC-based survivability evaluation model for information systems.Case analysis shows that the presented model can meet the practical needs from the users,and can give effective suggestions for the information system according to the evaluation results of system survivability.Therefore,survivability of the information system can be improved with limited resources and the tasks can be successfully fulfilled in hostile environments.