This invention relates to a recombinant microorganism having improved butanol production capacity and butanol production with the use of such recombinant microorganism with good efficiency. In this invention, the acetoacetyl-CoA synthase gene encoding an enzyme capable of synthesizing acetoacetyl-CoA from malonyl-CoA and acetyl-CoA and a group of genes involved in butanol biosynthesis that enables synthesis of butanol from acetoacetyl-CoA are introduced into a host microorganism.