New data on stratigraphy of Vendian (?) - Lower Paleozoic of S Ferghana (Tien-Shan) is considered. Various volcanites, silicites, linestones of Vendian-Amginian layer, Middle Cambrian Lower Ordovician linestones, Middle-Upper Ordovician grawackes, alevrolites and silicites are found tectonic fragments in the Hercynian thrust structure. Lower Paleozoic events are shown to be an initial development stage of the transition from Alai microcontinent to S Fergana ocean.-English summary