The aging process is driven at the cellular level by complex molecular damage that slowly accumulates with age for most living organisms. The main clinical signs of skin aging include wrinkling and irregular pigmentation, which are influenced by a combination of intrinsic and extrinsic factors (e.g. UV radiation, heat, smoking, and pollutants). Like UV radiation, smoking can result in extrinsic skin aging. Skin damage from long term smoking can result ―smoking face‖ and can cause facial skin to appear grayish and lines to develop around eyes and mouth, through damage to collagen fibers and elastin in the dermis. Significantly increased level of MMP-1 mRNA are observed in the dermal connective tissue of smokers compared with nonsmokers. Increased MMP-1 leads to the degradation of collagen and elastic fibers, which major extracellular matrix proteins in the dermis. However, there are still numerous challenges ahead in relation to understanding this complex biological process and hopefully these factors of skin aging approaches will allow detailed understanding of the mechanism underlying the hallmarks of aging and will facilitate future interventions for improving human health span and longevity.