Abstract: In order to investigate the mechanical property of frozen rock mass in western area,the particle size distribu- tion and pore distribution of typical red sandstone in western Mesozoic strata were analyzed with premier digital micro- scope. Uniaxial and triaxial compression test on frozen red sandstone and frozen cracked red sandstone with crack an- gle of 0°,15°,30°and 45° were conducted under temperature from -5 ℃ to -15 ℃ . The experimental results indicate that the strength of cracked or no cracked red sandstone increased linearly with confinement. Strength of frozen cracked red sandstone decreased with crack angle nonlinearly,when the crack angle was larger than 30°,strength decrease ex- tent was less. The strength and the lateral deformation of frozen cracked red sandstone were under the control of ice weak plane. The distribution characteristics of crack width and angle need to be investigated in engineering.