Proliferative response of vimentin expressing astrocytes to injury of the cerebral hemisphere was examined in mouse using H-3-thymidine autoradiography. Within the injury region the vimentin-positive astrocytes proliferation began on the 2nd day after injury, reached its maximal intensity on day 4 and its last evidence was recorded on the 8th postoperative day. The pattern of changes in the distribution of reactive proliferation of the astrocytes was also presented.