An L-amino acid is produced by culturing a Methylophilus bacterium which can grow by using methanol as a main carbon source and has L-amino acid-producing ability, for example, a Methylophilus bacterium in which dihydrodipicolinate synthase activity and aspartokinase activity are enhanced by transformation through introduction into cells, of a DNA coding for dihydrodipicolinate synthase that does not suffer feedback inhibition by L-lysine and a DNA coding for aspartokinase that does not suffer feedback inhibition by L-lysine, or a Methylophilus bacterium made to be casamino acid auxotrophic, in a medium containing methanol as a main carbon source, to produce and accumulate an L-amino acid in culture, and collecting the L-amino acid from the culture.