Provided is a self-optimizing computer system that can achieve ultimate optimization (improvement in the speed) by preparing a mechanism that can observe the behavior of the program execution in the self-optimizing computer system and optimize dynamically depending on the execution behavior of program. The self-optimizing computer system comprising multiple processing units, characterized in that each of the processing units operates as at least one of an operation processing unit for executing a program, an observation processing unit for observing the behavior of the program under execution, an optimization processing unit for performing an optimization process according to the observation result of the observation processing unit, and a resource management processing unit for performing a resource management process of whole of the system such as a change of the contents of execution.