In the norepinephrine (NA)-induced cardiac hypertrophy model, the overexpression of miR-376b-3p and the knockdown of MFF attenuated NA-induced mitochondrial fission and cardiac hypertrophy, which suggested that miR-376b-3p could improve mitochondrial fission and reverse cardiac hypertrophy by inhibiting the expression of MFF by binding to its 3’UTR. Here, MFF is linked to cardiac hypertrophy.