OBJECTIVE: Metformin, insulin, and insulin secretagogues do not alter HbA1c levels in glucokinase maturity-onset diabetes of the young (GCK-MODY). However, the efficacy of the new hypoglycemic drugs on GCK-MODY remains unclear. RESEARCH DESIGN AND METHODS: We describe a case of GCK-MODY with unchanged blood glucose under different therapies during an 8 years' follow-up. His HbA1c and biochemical indices under different hypoglycemic treatments were recorded. RESULTS: Oral glucose-lowering drugs, including thiazolidinediones, dipeptidyl peptidase 4 inhibitor, α-glucosidase inhibitor, and sodium-glucose cotransporter 2 inhibitor that had not been evaluated previously, did not improve the HbA1c level in this patient. However, the glucokinase activator dorzagliatin effectively and safely lowered his HbA1c level. CONCLUSIONS: Dorzagliatin was effective and safe in this patient with GCK-MODY, providing potential application prospects for precise treatment of GCK-MODY with dorzagliatin.