Lithospheric stress in Mongolia has been studied using mechanisms of 84 M_(LH)≥ 4 earthquakes that occurred in the 20 th century and instrumental seismic moments of 17,375 M_(LH)≥2.5 events recorded between 1970 and 2000.The M_(LH)≥ 3.5 earthquakes mostly have strike-slip mechanisms in southern and central Mongolia,with frequent reverse-slip motions in the west and normal slip in the north,especially,in the area of Lake Hovsgol.The principal stresses are,respectively,S_H>S_v>S_h in the center and in the south;high horizontal compression with S_H>S_h>S_v in the west;and a heterogeneous stress pattern with S_v>S_H>S_h in the north.According to seismic moments of M_(LH)=2.5 events,oblique slip generally predominates over the territory,at S_v≈S_H>>S_h,while frequent strike slip motions in the west record high horizontal compression(S_H>S_v>S_h).Earthquake mechanisms show the principal horizontal compression S_H to be directed W-E in the east,NE-SW in the central and Gobi-Altay regions,and approximately N-S in the west of Mongolia.The patterns of principal lithospheric stresses in the territory of Mongolia have undergone three events of dramatic change for a few recent decades,and these events were synchronous with three similar events in the Baikal rift system(BRS):in the latest 1960 s,latest 1970 s to earliest 1980 s,and in the latest 1980 s to earliest 1990 s.The seismicity of Mongolia has been controlled by superposition of variable stresses associated with rifting activity pulses in the neighbor BRS on the background of quasi-stationary super-regional compression. Lithospheric stress in Mongolia has been studied using mechanisms of 84 M_ (LH) ≥ 4 earthquakes that occurred in the 20th century and instrumental seismic moments of 17,375 M_ (LH) ≥ 2.5 events recorded between 1970 and 2000.The M_ (LH) ≥ 3.5 earthquakes mostly have strike-slip mechanisms in southern and central Mongolia, with frequent reverse-slip motions in the west and normal slip in the north, especially, in the area of ​​Lake Hovsgol. Principal interests are, respectively, S_H> S_v> S_h in the center and in the south; high horizontal compression with S_H> S_h> S_v in the west; and a heterogeneous stress pattern with S_v> S_H> S_h in the north. According to seismic moments of M_ (LH) = 2.5 events, oblique slip generally predominates over the territory, at S_v ≈ S_H >> S_h, while frequent strike slip motions in the west record high horizontal compression (S_H> S_v> S_h). Earthquake mechanisms show the principal horizontal compression S_H to be directed WE in the east, NE-SW in the central and Gobi-Altay regi ons, and approximately NS in the west of Mongolia. patterns of principal lithospheric stresses in the territory of Mongolia have undergone three events of dramatic change for a few recent decades, and these events were synchronous with three similar events in the Baikal rift system ( BRS): in the latest 1960 s, latest 1970 s to earliest 1980 s, and in the latest 1980 s to earliest 1990 s. The seismicity of Mongolia has been controlled by superposition of variable stresses associated with rifting activity pulses in the neighbor BRS on the background of quasi-stationary super-regional compression.