Provided is a transformant which can produce lactic acid with a high productivity without requiring neutralization with an alkali and is excellent in both of lactic acid production capability and growth ability and its production process, and a method for producing lactic acid by using the transformant. A transformant comprising 3 copies of a human lactate dehydrogenase gene that is introduced into a Schizosaccharomyces pombe host, wherein a gene encoding pyruvate decarboxylase 2 of the Schizosaccharomyces pombe host is deleted or inactivated.