Myelin proteins composition was examined in material of 20 autoptic cases at ages from 20 to 97 years. The technique of polyacrylamide gel electrophoresis and isotachophoresis was applied. In polyacrylamide gel electrophoresis a progressive increase starting at the age of 60 years of Wolfgram protein at the expense of Folch-Less proteolipid protein and DM-20 protein was observed. The myelin-associated protein started to increase in the 4th and 5th decade of life, returning therafter to values observed in younger cases. The isotachophoretic technique did not differentiate the changes observed in myelin protein in the course of aging.