Objective To investigate the expression of the three isomers of TGF-β in SD rat with different age and to explore their probable roles in skin aging. Methods Western blot was performed to detect the expression of TGF-β1,2,3 in the skin of 2-months old SD rats (youth group, n=6) and 18-months old SD rats (elderly group, n=6). Results The expression of TGF-β1 was significantly higher in youth group than in elderly group (1.91 ±0.67 VS 0.14 ±0.09, P<0.01). Negative expression of TGF-β2 was detected both in youth group and elderly group (0.16 ±0.07 VS 0.1 ±0.04, P=0.17). Positive expression of TGF-β3 was detected both in youth group and elderly group (0.95 ±0.20 VS 0.80 ±0.26, P=0.26). Conclusion The expression of TGF-β1 may play an important role in aging skin.