Disclosed herein is a method for extending the sugar chain modification of a lipid or a protein by introducing two or more glycosyltransferase genes in a biological organism (including animal-, plant- or microbial cells). Also disclosed is a recombinant plant with a potency to generate ceramide trihexoside and a method for generating ceramide trihexoside using the plant. Methods for synthetically preparing ceramide trihexoside utilizing a transgenic tobacco prepared by constructing an expression vector with the ORF of human- or animal-derived .alpha.1,4-galactosyltransferase gene (.alpha.1,4 GT) for plants and subsequently introducing the vector into tobacco using a genetic approach for plants and methods for the mass-scale production of ceramide trihexoside are also disclosed herein.