The analysis of possible morphogenesis of the different structures in human yolk sac tumor has been considered. The author has supposed that features of blood vessel microarchitecture formation and perpetual differentiation of tumor cells or theirs functional modification play a crucial role in the morphogenesis of YST. The immunohistochemical investigation of some stem cells markers has showed the necessity of accounting of their distribution pattern in various cellular structures for the differential diagnosis of morphogenetical steps of YST. The growth of tumor cells differentiation rate correlates with increasing of stem cells markers expression as well c-kit > OCT4 > CD30 > PLAP.