Research on compression hydrostatic structural elements of magnesium alloys for the three samples of alloy AZ91 and the three samples of alloy AZ31 -shaped flanges with the following parameters : the upper surface of the sample - 225 mm ², clearances on the sleeve in a matrix - 10um , strain rate - 0.1 mm / min , die temperature : 80 , 150, 200 + -10 degrees Celsius , the maximum stress of about 400 MPa. In the latter case, the force control is applied instead of controlling the position ( 2kN/min ) but remain in further studies with positional control . Acoustic emission was measured at a frequency of 160 kHz for a period of about half an hour , until the maximum force . In the case of acoustic research , for comparative purposes , it was necessary to carry out the calibration measurement on the sleeve of carbon steel. The value of the resultant force ( 90kN ) ensures the resilient nature of the deformation of steel, therefore, to exclude possible errors of interpretation akustograms magnesium alloys , e.g. due to friction. Examined the nature of the compression curves and comparing them with akustogramami for magnesium alloys and a small change in the dimensions of the sample shows that the deformation took place , and the peaks of akustogramach suggest twinning as the main deformation mechanism .