Objective To observe clinic pathological features of seminoma of the testis.Method Research was conducted by analyzing clinic pathological features and morphological features in 6cases with seminoma of the testis.Results The ages of 6patients ranged from 25 to 42years old.The examinations showed that tumors manifested themselves as oval with maximum diameter of 15 cm

complete capsule

and off-white color on cut surface;had classical clinic pathological features of seminoma when examined by microscope;presented positive placental alkaline phosphatase（PLAP）and positive CD117 by immunohistochemistry test

1case of focally positive alpha-fetoprotein（AFP）

1case of focally positive CD30

while negative human chorionic gonadotropin（HCG）

CKpan

lens culinaris agglutinin（LCA）

and vimentin.Conclusion Middle-aged men are high incidence population of seminoma of the testis.Cryptorchidism is the high risk factor.The study mainly depends on typical pathologic characteristics and results of immunohistochemistry test.