The data on chemical composition of atmospheric aerosols (AA) and atmospheric precipitation (AP) were analyzed to identify the sources of aerosol coming to the Baikal nature territory. Irkutsk is supposed to be a typical industrial center of Eastern Siberia, the station Mondy is taken as a background site, and the station Listvyanka represents a rural settlement influenced by a large industrial center. The factor analysis of the AA and AP composition was used to identify the main sources (factors) of atmospheric pollutants. Four main factors were distinguished for the points under consideration: soil, gas-phase, anthropogenic, and local. The role and composition of the factors vary for aerosols and precipitation. Using the statistic methods (STATISTICA software package) cyclic (seasonal) components of observational series were determined and interrelations between chemical composition of aerosols and precipitation at the point of observation were estimated. The role of advective (circulation) factor was assessed taking into account four geographical groups of air mass transfer trajectories that were identified before. The anthropogenic sources were studied in sum. Further it is planned to reveal the contributions of mobile sources (vehicles), energy, and other industrial enterprises.