In 176 human fetuses at prenatal weeks 16-23, the quantitative study was performed to evaluate the changes of topography of the hearts chambers, septum and valves, aorta, pulmonary trunk and superior vena cava. Te method of N. I. Pirogov, macro-microscopical dissection and preparation of the histotopographical sections in three mutually perpendicular planes were used. As a result of this study, the data on holotopy, skeletotopy and sintopy of the heart and major mediastinal vessels in the early fetal period of human ontogenesis, were obtained. Tese data may be used as reference parameters during the diagnostic ultrasonographic and magnetic resonance tomographic studies of fetuses and during surgical operations performed on fetuses.