We have mapped the Large Magellanic Cloud (the LMC) in the
 [C II] 158 mm fine-structure line with the Balloon-borne
 Infrared Carbon Explorer (BICE) system. The [C II] line emission
 was detected over most of the LMC.  The mean [C II]/CO (J = 1-0)
 line intensity ratio was 23000, 18 times larger than the
 typical value observed in the Galactic plane (1300).
  This result implies that each clump of the molecular clouds
 in the LMC has a larger C+ envelope relative to its CO core
 than those in our Galaxy. Lower dust abundance due to its
 lower metallicity allows UV photons, which convert CO molecules
 into C+ ions, to penetrate deeper into the clumps in the LMC
 than in our Galaxy.
 However, the LMC has different points from normal spiral
 galaxies other than metallicity. The LMC is a irregular,
 and has no spiral arms, which are shown by density wave.
 In spiral arms, where density of interstellar clouds are high,
 formation of molecules may be enhanced. Hence, the dominant
  factor enhanced [C II]/CO intensity ratio in the LMC might be due
 to the luck of strong density wave.
 The galaxies with low metallicity are not restricted to
 irregulars. Observing the galaxies which has low metallicity
 and spiral arms is good method to know the effect of
 density wave for [C II]/CO intensity ratio. Nearby
 galaxy M33 is one of such galaxies.