Abstract: For working out the problem of service dynamical composition and re-composition in service orient embedded system integration process,a chemical service composition model was proposed．By imitating the manner of chemical synthesis,molecular decomposition,chemical replacement and molecular reproduction in the chemical reactions,service behaviors in the composition process like composition,decomposition,replacement,replication and their operating and evolution mechanisms were formally described．Based on these service behaviors and the petri-net method,the service evolution model was proposed to describe the compound composition process with services reliance and parallel situations．And then,as an illustration for meeting the requirements of service self-adaptive composition in command and control system,an experimental system which is called chemical service composition system (CSCS) was designed and implemented to verify the availability and analyze the performance of the models and algorithms．The results of experiment show that the chemical service composition model satisfies the application request of service self-adaptive composition in command and control system,and effectively enhances the flexibility and reconstitution of embedded systems.

Key words: Service composition,Chemical reaction mechanism,Service behavior model