Abstract: Testicular germ cell tumor (TGCT) is one of the commonest malignant tumors among young men in industrialized countries. As most tumors are formed in fetal development stage, it is difficult to have an insight into the pathogenesis. By reviewing the recent related reports, we discussed several etiologic factors of TGCTs, including race, geography, environment, related genes and signaling pathways, cancer stem cells (CSC), the niche for spermatogonial stem cells (SSCs), etc, to support investigating pathogenesis and treatment of TGCTs.