Adenoid cystic carcinoma is a malignant salivary gland tumor with typical histologic patterns. The majority of these tumors occurs in the minor salivary glands. especially mucosa of the hard palate. The authors experienced the patients, who complained the tumor-like soft tissue masses on the palatal and mouth floor area. After careful analysis of clinical, radiological and histopathological findings, we diagnosed them as adenoid cystic carcinomas in the minor salivary glands, and obtained results were as follows : 1. Main clinical symptoms were a slow growing soft tissue mass with normal intact mucosa on the palatal area, and soft tissue mass with mild pain on the mouth floor area. 2. In the radiographic exarnminations, soft tissue masses were observed with invasion to adjacent structures, and moderate defined, heterogeneous soft tissue mass with enhanced margin, respectively. 3. In the histopathologic exarnminations, dark-stained, small uniform basaloid cells in the hyaline or fibrous stroma were observed as solid and cribriform patterns, respectively.