Abstract: The SARS virus origin which obviously differs from the theory of out-space origin and the theory of wildlife origin was theoretically discussed based on principles of pollution evolution ecology,pathogenesis and infectant characteristics of SARS,and some relevant experimental evidence. It emphasizes on the fact that increasingly combined pollution in China provides a substantial basis for virus evolution. Gene recombination and fusion of more than one virus in ecosystems should take charge with the origin of a SARS virus. In particular,a common cold or influenza virus can acceleratedly changed into a superpower common cold or influenza virus through genetic mutation and gene recombination by increasingly combined pollution. This work can be useful for human beings to overcome SARS in theory.

Key words: SARS, Coronavirus, Gene recombination, Life evolution, Combined pollution