We received and treated 18 cases of lienal hydatidosis in recent years.Fifteen patients were treated surgically:7 cases underwent removal of endocyst following the aspiration of cyst fluid and the ectocystic wall opened or filled with greater omentum,2 cases with small cysts,underwent closure of ectocyst by suture following the complete cleaning of the residual cavity,One case received laprascopic cystectomy and 5 cases underwent complete resection of the spleen.All of the surgical cases attained complete healing.In this paper the etiology,diagnostic criteria and differential diagnosis and the improved method of surgical treatment are discussed.