Objective To obtain fully protected glyco amino acid for synthesis of various glycopeptides. Methods With galactose as the initial compound, the full benzyl protected β-D-1-thio-galactopyranoside (5) was obtained after 5 steps of reactions. Then it was used as donor for glycosylation with Fmoc-Ser-OAlly to yield fully protected glyco amino acid. Finally, the allyl group was removed to obtain the objective glyco amino acid (1). Results The structures of the intermediate and objective compounds were confirmed by MS, ¹HNMR and ¹³CNMR, and the target glyco amino acid was obtained. Conclusion The present synthetic method is simple to perform and can be widely used; meanwhile, the protective base can be easily removed. The target glyco amino acid is suitable for synthesis of various glycopeptides.