We examine the influence of rifting processes on the location of the lakes along the eastern shores of Lake Baikal, and on the formation of chemical composition of the waters contained by them. It is determined that the lakes are in different geologo-hydrological conditions. It is established that their water areas liberate gas mainly consisting of methane and nitrogen; increased content levels of helium were discovered in free gas in areas where deep-seated faults occur. Manifestations of mud volcanism associated with methane discharges were observed. It is shown that the faults serve as the vehicle to discharge into small lakes fissure-vein waters which impart a peculiar kind of geochemical appearance to the water, and thick deposits of sapropel were produced under the warming effect of thermal waters. In the lakes there is taking place a transformation of chemical composition along the soda direction. In the water body with a retarded water exchange, the mineralization of the waters exceeds 1 g/L. On the eastern shore of Baikal’s Southern Holow, fissure-vein waters are not discharged, chemical composition is formed as a result of drainage of the Kabanskii bog massif, and the waters refer to the hydrocarbonate magnesium-sodium-calcium type. The emissions of free gas on this territory are dominated by methane.Keywords: rifting processes, gas, temperature, sapropel, mineralization.