Abstract: Objective: To investigate the clinicopathological characteristics of primary ovarian strumal carcinoid(POSC).Methods: The clinicopathological characteristics of POSC in 4 cases were analyzed by light microscopy,immunohistochemistry and special stains.Results: The patients' clinical manifestations were lower abdominal pain,and no constipation and carcinoid syndrome.Ovarian cystic masses torsion was the initia symptom in 2 cases.The goiter and carcinoid tissue were transition,part cancer cells arranged in island or beam.The borderline mucinous cystadenoma in 1 case and mature teraloma in 3 cases were found.The neural cell adhesion molecule of immune phenotype cancer cells,synaptophysin,chromogranin and neuron specific enolase were positive.Conclusions: POSC is a rare germ cell tumor,which should be differentiated from granulosa cell tumor and Sertoli-Leydig cell tumor.HE and immunohistochemical stain will contribute to the diagnosis.