Background: Rosacea is common chronic disorder primarily of the convexities of the central face. However there have been few studies about clinico-histopathological correlation and epidermal barrier function of rosacea in Korea Objectives: We investigated clinical and histopathological features and epidermal barrier function of rosacea in Korean patients Methods: We performed a clinical study in 100 new patients with rosacea who visited our clinic from May 2010 to December 2011. Skin biopsy was performed in 48 patients. To evaluate skin barrier function, transepidermal water loss was measured in 94 rosacea patients Results: Rosacea occurred predominantly in females, with the gender ratio with 1:3.55. In clinical manifestations, persistent erythema and burning/tingling sensation was most common primary and secondary feature respectively. In severity grading, overlap subtype showed more severe grade than erythrotelangiectatic or papulopustular subtype. The irritation after application of usual cosmetics was found in 52% of rosacea patients. In the histopathologic analysis, the changes in epidermis such as spongiosis and acanthosis were found in 68.8% of rosacea patients. TEWL of rosacea lesions were increased, comparing with normal skin. Rosacea patients with cosmetic irritation showed higher TEWL than those without cosmetic irritation Conclusion: Epidermal change and the increased TEWL of rosacea lesion suggested impaired skin barrier function and it could be the cause of sensitive skin.