Alveolar bone resorption inhibitors for topical injection by the alveolar mucosal needling method which contain as the active ingredient a bisphosphonic acid derivative or its salt; and alveolar bone resorption inhibitors to be topically injected into a human periodontal tissue which contain a bisphosphonic acid derivative or its salt in such a concentration as being as low as causing acceptable topical stimulation to the administration site (i.e., the human periodontal tissue) and yet sufficient for the exertion of the effect of inhibiting the alveolar bone resorption by topical injection.