1, salivary gland inflammation, according to its nature is divided into: purulent, viral and specific infection. 2, salivary gland stones, is a series of lesions caused by the occurrence of calcified masses in the gland or duct. 85% occurs in the submandibular gland, followed by the parotid gland, occasionally seen in the minor salivary glands, sublingual glands are rare. Salivary stones often obstruct salivary drainage and cause acute or chronic recurrent inflammation of the gland secondary to infection. The causes of stones are: the presence of calcium deposit centers; salivary retention; body metabolism; enzyme dysfunction and pH changes, etc. 3. salivary gland injury and salivary fistula salivary fistula: saliva does not drain into the oral cavity through the duct system and flows to the surface of the cheek skin. Salivary fistula etiology: First, injury, such as maxillofacial laceration or surgical trauma. The second is inflammation, which is caused by septic infection that destroys the gland, ducts and other structures. 4, oral dry syndrome Oral dry syndrome is an autoimmune disease, characterized by the progressive destruction of exocrine glands, resulting in dry mucous membranes and conjunctivae, and accompanied by various autoimmune signs. Primary oral dryness syndrome: the lesion is limited to the exocrine gland itself. Secondary oral dry syndrome: accompanied by other autoimmune diseases. 5.Salivary gland neoplasm-like lesions There are salivary gland mucous cyst, parotid cyst, benign hypertrophy of salivary gland and other diseases. 6.Salivary gland tumor Tumor is the most common disease in salivary gland tissue, most of which are epithelial tumors, and tumors of mesenchymal tissue origin are rare. The pathological types of salivary gland epithelial tumors are very complex, and different types of tumors have different clinical manifestations, treatment and prognosis.