The Baikal Group is one of the most important stratigraphic units in the geology of East Siberia ( Upper Riphean) �� This paper focuses on litological-facies features based on the analysis of organic remains ( stromatolites�� microphitolites and microfossils) ��in order to better precise the age and environmental deposit conditions of the Baikal Group�� The results are used to draw a correlation between all the Precambrian of deposits of the South of East Siberia�� The stratigraphy of the Baikal Group is then compared to the geodynamic evolution of this region��characterized by the break-up of the supercontinent Rodinia and subsequent opening of the Paleo-Asian Ocean�� Stratigraphic analogs to the Baikal Group display in most areas deposits of various minerals ( complex ores��phosphoresces��bauxites etc�� have been dated of the same age) ��so the present study would also provides an economic interest��