N-Heterocyclic carbenes(NHCs) and their stable transition metal complexes rank among the most popular subjects for research in organometallic chemistry that have been widely used in the field of catalysis. Researchers are investigating NHCs metal complexes with increasingly complex NHCs components, adding new functional substituents to the NHCs heterocyclic ring. Sugar compounds are extremely abundant molecules and well known for their biocompatibility, water solubility, chirality and nontoxicity. It is not surprising that sugar substituents have been introduced into NHCs(sugar-based NHCs) to increase water solubility and chirality. Sugar-based NHCs and their metal complexes show great potential in the fields of catalysis and pharmacology. To understand the success of sugar-based NHCs, this review first presents the important research progress in sugar-based NHCs precursors and NHCs metal complexes containing monosaccharides such as D-glucopyranose, D-galactopyranose, β-glucosamine, galactosamine, and aminomannose are discussed. Overview, sugar-based NHCs and their metal complexes are divided into five categories according to the carbon-linked of sugar with fused ring(including C-1, C-2, C-3, C-6, and others). Then the main synthetic methods, handling, structure, and catalytic activity of sugar-based NHCs and their metal complexes are discussed in detail, roles of the sugar moiety, NHCs ligand and transition metal complexes related to these properties are highlighted. Finally, the catalytic activity, especially in asymmetric catalytic reaction, and the development trend of sugar-based NHCs precursors and NHCs transition metal complexes are prospected.