Abstract: Survivability refers to the ability for a network system to provide essential services to end users in the presence of failures and/or attacks,and recover full services in a timely manner.According to the requirement of the survivability of MANETs,a more comprehensive model for quantitative evaluation of survivability is proposed.The proposed model considers various types of faults and connection states of mobile hosts,and uses the continuous time Markov chain(CTMC) to describe the survivability of MANETs in a precise manner.Finally,the availability of steady state,connectivity probability,failure frequency and average number of faulty nodes are simulated in MATLAB.