Abstract： Objective To explore the diagnosis and combined treatments on the intracranial immature teratomas.Methods The clinical data of 40 intracranial immature teratomas were collected from Jan.2002 to Dec.2008,and 36 were followed up.According to the clinical symptoms,signs,serum tumor markers and radiology,the immature teratomas were diagnosed and the followed treated courses were different depending on the tumor volume and symptoms.Results All the 36 cases were operated and immature teratomas were confirmed by the histopathology.In the giant tumor group ( 26 cases,which the tumor diameter larger than 3 cm),the cases were divided into group A and group B.In the group A,the patients were in a relative good condition and the tumors didn' t invade the adjacent cerebral tissues,so,the operation was recommended first and the chemo - and radio - therapy were followed.In the group B,when the patients were in a poor condition and tumors invade the adjacent cerebral tissues obviously,chemotherapy were recommended first and when the tumors shrink,the operations were followed and then treated by the combined treatments.In the small tumor group ( 10 cases,which the diameter less than 3 cm),operations were recommended first and the combined treatments were followed.Conclusions Chemotherapy is firstly recommended on the intracranial immature teratomas,and when the tumors shrink and pseudo - membranes are formed,operations are followed.Postoperatively,combined treatments could obviously extend the patients' life.