High-performance frontal analysis (HPFA) was used for the protein binding study of catechin hydrate and genistein to human serum albumin (HSA). The experiment was performed on a Develosil 100Diol-5 column, and sodium phosphate buffer (pH 7.4 and ionic strength of 0.17) was used as the mobile phase. The mixtures of the drug-HSA solution were directly injected into the HPFA column, the HSA was eluted first and the unbound drugs were eluted out as a trapezoidal peak with a plateau region. The unbound drug concentration was determined from a plateau height of the plateau region and the experimental data were fitted by Scatchard equation. The binding constants (K) and binding affinities (nK) of the drug to HAS were K=1.32×10^(4) (L mol^(-1)), nK=0.47×10^(4) (L mol^(-1)) for catechin hydrate, and K=5.17×10^(4) (L mol^(-1)), nK=2.14×10^(4) (L mol^(-1)) for genistein.