As the front line of protecting the human body against outer environment, stratum corneum (SC) is relentlessly attacked by the external stressors. Along with natural stressors, such as low humidity, abrupt temperature change, and sunlight, various artificial stressors also impact the skin barrier function. While the cosmetics are one of the most common “stressors” possibly disrupting the epidermal permeability barrier function, potential beneficial effects of cosmetics on skin barrier function are also repeatedly reported. Supplementation of SC intercellular lipids with barrier creams, which show either compositional or structural similarity to those of SC lipids, can accelerate the recovery of damaged barrier functions. Bioactive ingredients stimulating the epidermal sphingolipids synthesis can also improve the skin barrier functions. Anti-oxidants and anti-inflammatory molecules, either directly or indirectly, protect skin barrier function against external stressors. In this review, protecting effects of cosmetics on skin barrier function and their possible defending mechanisms will be briefly discussed. An ideal combination of “barrier cosmetics” will be also suggested.