Abstract: The present invention provides a method for modifying melamine derivatives that can produce N-substituted melamine derivatives by introducing a substituent group to melamine or N-substituted melamine derivatives. The method is characterized by heating melamine or an N-substituted melamine derivative and an alcohol in the presence of a mixed catalyst comprising a hydrogenation catalyst and a dehydrogenation catalyst and hydrogen to allow reaction or heating melamine or an N-substituted melamine derivative and an alcohol in the presence of a hydrogenation catalyst and hydrogen with addition/coexistence of a metal to allow reaction. The compound groups obtained by introducing a substituent group to the amino group of melamine derivative with an alcohol by the method of the present invention can be used widely as intermediates of fine chemicals such as various agricultural chemicals, medicines, dyes, paints, etc. and as various resin materials and flame retardant materials.