Abstract: The interpretation of aerial photographs of different years and analysis of maps helped us to obtain reliable information about the rates and intensity of degradation of glaciation and change in the structure of glacier moraine complex in the fourth large glacial systems of the Northern Tien Shan in the second half of XX century. During the period of 1955/56–2004 the area of glaciation in the glacial systems of the Kazakhstan part of the Ili River basin reduced from 926.13 km2 to 570.15 km2 , i. e., by 356 km2 or 9.23 km2 per year. A retreat of glaciers is accompanied by intense cryogenic processing of the bottom glacial deposits that outcropped on the surface.