Nature immune system is an excellent defense system. Inspired by the two immune response mechanisms of nature immune system, a new design of an artificial immune system-COMUS-has been brought forward. COMUS mainly comprises of two parts: PIRM and SIRM. It could detect both known and unknown intrusions. And it could automatically extract signatures for the abnormalities which have not been encountered before, and generate scripts to describe the abnormalities and remember them to response much more quickly next time. COMUS is adaptive which could automatically update the application?s profile to keep up with the changing environment. And automatically or manually updating the Signature Lib of Abnormal Behaviors will make COMUS get the ability to identify new attacks. Experiments are performed to evaluate the system and results are reported.