The present invention discloses a composition comprising a filler and Botulinum toxin for alleviating skin wrinkles or aging or treating neuromuscular diseases. The composition according to the present invention resolves neuromuscular diseases, aging or skin wrinkles caused by two types of causative factors through a single injection. At the same time, the composition according to the present invention has a synergistic effect by which one component improves the efficacy of another component. Therefore, the number of injections is decreased to thereby enhance the convenience of patients and reduce costs.