The administration of apelin at 1.0 μmol/kg for 4 weeks to CKD mice suppressed the increase of atrogin‐1 and myostatin, increased apelin and Apj mRNA expression at 30 min after apelin administration and significantly ameliorated weight loss and a decrease of the cross‐sectional area of hindlimb skeletal muscle. The gene discussed is APLN; the disease is chronic kidney disease.