The submarines were strategically regarded by R.O.C. Navy as serving an edge of ”effective deterrence” from China attack, therefore having the decisive impacts upon safeguarding national security and interests of Taiwan. Nevertheless, since the statement of selling eight diesel-electric submarines to Taiwan made public by the U.S. in April, 2001, the arms deal has long been a controversial issue in Taiwan bipartisan system and recurrently put on pending by the Legislative Yuan. With the theory of levels of analysis, this article is to historically review and account for Taiwan's strategic concepts of submarine procurement and construction packages; the translation into the evolution of endeavors over a several-decade period; and the potential impacts on the triangular tensions involving the U.S., China and Taiwan in the future.