Abstract: Evolution is a kind of innovation indeed. Computer numerical calculation, programming, data storage, knowledge reasoning are some aspects in the evolution progress of computer software. Computer software achieves its evolution by innovation transformation (forward)，which empowers the computer’s capability of solving problems. Innovation transformation is accomplished by regression transformation (backward), which maps the method of solving complex problems into the original function of computers. Though the computer is very powerful, its basic theory is quite simple and straightforward. 

Key words: computer software; evolution progress; innovation transformation (forward); regression transformation (backward); extension transformation