Background: Modern methods of visualization allow to study anatomy of the developing child. Besides prenatal interventions demand new data on anatomy of internal organs of the fetus. Material and methods: The torsos of 20 fetus 16-22 week gestation of both sexes became material of reseach. This material was divided into two aged groups: 16-17 and 22 week of development (on 10 fetuses in each group). The main method of research was the macromicroscopic preparation, a number of additional data was received by using of the gistotopographical method and the modifying method of cuts according to N. I. Pirogov. Results: In 90% of cases the pyramidal shape and in 10% cone-shaped of the thorax was observe. The size of the infrasternal angle in group of 16-17 week fetuses changed ranging from 89º to 130º. This parameter for group of 22 week of development was within the limits of 75º-125º. The sternum in cause of 16-22 weeks fetuses consists of three parts: manubrium, body and xiphoid process. Comparing data of width of intercostal spaces and height of ribes, it is possible to note that intercostal spaces are more than ribs height to all projective lines in both age groups. The intercostal spases are 1,5-2 times more than rib height in some places of a thorax. Conclusions: The thorax skeleton has the following features in the intermeddiate fetal period of person ontogenesis: 1. Wide intercostal spaces; 2. Discrepancy of serial number of the rib with number of a vertebra of this level (to parasternal, midclavicular and midaxillary lines); 3. The obtuse infrasternal angle and costal arches extending in the parties; 4. Asymmetry of a thorax.