To further explore the possible mechanism of miR-199a-5p in GDM, we used bioinformatics methods to predict the target genes of miR-199a-5p, and found that MeCP2 has a response element recognized by miR-199a-5p, we used dual fluorescence The targeting regulation relationship between miR-199a-5p and MeCP2 was verified by the nephelase reporter system. The gene discussed is MECP2; the disease is gestational diabetes.