In order to determine if the development of β-adrenergic receptors may explain the catecholamine evoked contracture of denervated mammalian skeletal muscle, the binding capacities and dissociation constants of β-adrenergic receptors of innervated and denervated rat skeletal muscle membrane preparations were determined by using [ 3H] dihydroalprenolol. The dissociation constants of [ 3H] dihydroalprenolol binding to innervated and denervated muscle microsomal suspensions were similar. The maximal number of binding sites increased from 27 pmol/g protein to 85 pmol/g protein following 25 days denervation. These results suggest that motor nerve may be involved in part, in the regulation of β-adrenergic receptors in skeletal muscle membrane preparations.