Abstract: It is unavoidable that there exist faults in software systems, and how to provide continuing error-free service when software system breaks down or is disturbed by the external perturbation, is an urgent problem of the theory. Networks of static function-call and weighted networks from dynamic software execution are of small-world and free scale.Based on the model of coupled map lattice, the formation mechanism and propagation behavior of cascading failures in the software system were studied to improve the credibility of software testing based on critical node.

Key words: Complex network, Small-world effect, Scalcfrec property, Trusted software, Cascading failures, Coupled map lattice