Objective: To investigate the clinicopathological features of embryonic carcinoma or germ cell tumors with embryonic carcinoma component. Methods: Clinical data of 45 patients with embryonic carcinoma (EC) or germ cells with EC component were collected. The relevant cases were analyzed by histology and immunohistochemistry, and the prognosis was followed up. Results: Twenty-eight cases of EC or germ cell tumors with EC component originated from gonads (27 cases from testis, 1 case from ovary) and 13 cases from extra-gonads (10 cases from central nervous system, 1 case from mediastinum, 1 case from vertebral body, 1 case from retroperitoneal); 4 cases were of metastatic origin (2 cases from inguinal lymph nodes, 1 case from retroperitoneum, 1 case from lung). There were 12 primary cases of pure EC, 29 primary cases of mixed type germ cell tumor with EC component including 18 cases of EC mixed with 1 type of germ cell component, 10 cases with 2 components, and 1 case with 3 components. The proportion of tumor components mixed with EC were 75.9% (22/29) for teratoma, 34.5% (10/29) for yolk sac tumor, 20.7% (6/29) for seminoma, and 10.3% (3/29) for choriocarcinoma, respectively. The immunophenotype of EC or EC component was spalt-like transcription factor 4 (SALL4) (45/45), octamer-binding transcription factor 4 (OCT4) (45/45) and CD30 (43/45), and the average positive rate of Ki-67 was about 80%. After follow-up, 7 patients had lymph node metastasis, 1 patient had abdominal metastases, and the metastatic components were all EC, of which 3 patients died. Conclusion: EC always mixes with other types of germ cell tumors, the most common mixed component is teratoma, pure EC occurs almost in the testis. the diagnosis of EC or germ cell tumor with embryonic carcinoma component mainly relies on histological morphology and immunohistochemical expression. The degree of malignancy of EC is often higher than that of other germ cell tumor components, which is prone to metastasis and has a poor prognosis.