Strain accumulation data for the AlMg6 alloy under isothermal loading are presented. The recorded realtime parameters of the experiment are the load and the strain. A sample has been loaded by a shear stress, and the shearing strain has been measured. Loading is performed isothermally within the temperature range from 25 °С to 500 °С. It is shown that macroscopic strain jumps provide the main contribution to strain accumulation at low temperatures. Along the monotone strain accumulation, the macroscopic strain jumps with their significant contribution to the overall deformation of the sample are observed. When the temperatures are 300 °С and higher, the strain accumulation behavior undergoes the following changes: the strain increments exponentially without clearly visible strain jumps. However, the strain increment allows this stage of strain accumulation to be treated as a quasi step-like stage. It is explained by the fact that due to increasing of the temperature of isothermal time monotone accumulation areas become smaller until they merge completely into single fast quasi step-like stage of accumulation.