1,2,3-Triazoles are a kind of five-membered N-heterocycles featured with unique properties in biology and material science.They have played more and more important roles in the fields of medicine,pesticide,and materials since the Cu-catalyzed diploar cycloaddition reaction of azide and alkyne was founded by Sharpless and Medal groups,respectively.4-Monosubstituted 1,2,3-triazole is considerably important in its family,especially because of its structural merits of widely facile modifications.The synthesis of 4-monosubstituted 1,2,3-triazoles based on different reaction types and substrates,including cycloaddition of alkyne with azide,cycloaddition of nitroolefin with azide,cyclization of hydrazone with amino derivatives,and N1-substituent removal of 1,4-disubstituted 1,2,3-triazoles are reviewed.The substrate scope,limitation,and representative mechanism are also discussed.