The antrolith is a rare disease in the maxillary sinus. We experienced a 67-year-old female whose chief complaint was a intermittent dull pain of clinical, radiological and histological findings, we diagnosed it as antrolith in the left maxillary sinus and obtained results as follows: 1. Three radiopaque substances in the left maxillary sinus was revealed as 'Antroliths'. 2. These antroliths were movable in the left maxillary antrum and combined with maxillary sinusitis. 3. We supposed it internal origin of nidus in this case.