Smilax china is known for its excellent antimicrobial, antioxidant, and anti-inflammatory properties. As a foundational study for applying the functionality of Smilax china extracts to cosmetics, it is necessory to investigate the concentration-dependent skin permation characteristics of the flavonoids in the extract, namely quercetin, catechin, and naringenin. Therefore, it serves as a crucial method for conducting this basic research on the functional aspects fo Smilax china extracts for cosmetic applications. This investigation focused on examining the percutaneous permeability characteristics of flavonoids originating from Smilax china. Applying Marzulli's definition, the Kp value of quercetin was categorized as "fast" at 0.1 mg/mL and "moderate" at 0.2 and 0.4 mg/mL. Notably, the permeation rate exhibited a decline with increasing concentration. For naringenin, Flux values were 0.69, 1.07, and 1.42 ㎍/hr/cm2 at concentrations of 0.1, 0.2, and 0.4 mg/mL, respectively, with corresponding Kp values of 6.95, 5.34, and 3.56. Naringenin's Kp value fell into the "moderate" category across all concentrations, and as observed with quercetin, the permeation rate decreased with higher concentrations. Likewise, for catechin, Flux values were 0.75, 1.09, and 1.66 ㎍/hr/cm2, and corresponding Kp values were 7.55, 5.46, and 4.16. Catechin's Kp value was consistently classified as "moderate" across all concentrations. The efficacy of quercetin, catechin, and naringenin, active ingredients in high-performance and anti-inflammatory Smilax china extracts, was found to exhibit skin penetration properties above the average. This confirms their suitability as excellent natural materials for use in functional cosmetics, given their outstanding capabilities in preventing acne and reducing inflammation.