A preparative high-speed counter-current chromatography (HSCCC) method for separation and purification of phenolic acids from the Chinese medicinal herb Smilax china was successfully established by using n-hexane–ethyl acetate–methanol–water (1:2:1:2, v/v/v/v) as the two-phase solvent system. The experiment yielded 26.7mg of gallic acid, 16.5mg of protocatechuic acid, 21.8mg of caffeic acid, 31.3mg of gentisic acid, and 24.1mg of trans-o-coumaric acid from 250mg of crude extract in one-step separation, of each at over 98% purity as determined by high-performance liquid chromatography (HPLC). The structures of these compounds were identified by electron spray ionization mass spectroscopy (ESI-MS), 1 H and 13 C nuclear magnetic resonance (NMR).