Objective To analyze the imaging findings and pathological basis of seminoma and improve the understanding and diagnostic accuracy.Methods The imaging findings of seminoma in 67 patients proved by histopathology were analyzed retrospectively.The tumor location,size,contour,periphery,density or signal and contrast enhancement patterns were evaluated,and these were compared with the pathological results.Results All of the 67 cases were male.46 cases were located in testicular,10 cases in the pelvic cavity,6 cases in the peritoneal and retroperitoneal,4 cases in the mediastinum,1 case in the brain.On non-enhanced CT,testicular lesions appeared to be nodular or lobular masses with clear margin.Some cases showed cystic-solid masses.And the solid component was located in the edge of the lesion,and the irregular necrosis areas of low density was located in the center.Fat and calcification component were not found in the mass.After contrast administration,the masses showed heterogeneous enhancement.The thickened and tortuous testicular arteries were seen in 11 cases in arterial phase,and thickened and twisted testicular veins were seen in 9 cases in the venous phase.The imaging findings of the mass at the other location were without features.Conclusion Testicular seminoma has significant characteristics,thickened testicular arteries and/or draining veins on enhanced CT can help the diagnosis.Imaging features of extragonadal primary seminoma are not characteristic.Combined with clinical history and signs,it is possible to improve the diagnostiic accuracy of seminoma.