This study was carried on Rattus norvegicus as a model for aging forty eight were used to study changes in their skin and haemopoitiec tissue in the bone marrow during aging. Quantitation of DNA was performed using Feulgen reaction in the nuclei of stratum basale of the skin. It was found that there is an increase in the quantity as measured by optical density from (O.438+0.048) nm at one month age to (O.711+0.053) nm at 24 months age. Changes in epidermal thickness showed a decline in the mean thickness from (17.3+3.18) um at one month age to (lO+1,51) um at 24 months age. These changes were associated with changes in the alignment and the orientation of collagen fibres in the dermis as shown by interference microscopy. Collagen fibres seem to be getting more bizarre in alignment with age. Chromosomal analysis showed the presence of chromosomal abnormalities early in the young groups. These abnormalities seems to increase in incidence with aging, the number of abnormal cells increases with age and the level of hyperploidyal cells increases too. These findings were discussed as observation in aging skin and haeraopoltlec tissue and, their implication in the aging process.