Comparative Advantage Theory has been controversial for its confused definition and identification path and lack of empirical tests. This paper analyzes mechanisms of revealed and potential comparative advantage, and conducts spatial econometrics test based on space-time evolvement of comparative advantages of regional manufacturing industries. The results indicate that technology, factor endowment, scale economy, agglomeration effects and institutional factors are sources of revealed comparative advantage. Therefore, comparative advantage strategy of regional economy development should not exclude the impacts of multi-factor, and the driving mechanism is diverse instead of exclusive.