Abstract: Two preparative HPLC model for proteins are discribed. (1) Under condition of volume overloaded on column, the preparative ion exchange and reversed phase chromatography for proteins on column, the volume of the injected sample may be so large that eluted peaks are significantly wider than those from analytical sample. Although the solute concentration is lower, but we still can get more pure protein. First the preparative ion exchange chromatography was prepared trypsin inhibitor from crude soybean by Qme-PEI-si-200(30 μm), under condition of volume overloaded on column. The column were eluted with a gradient from 0.01 mol/L Tris-HCl pH 8 to 0.5 mol/L NaCl pH 8, 40 min, at flowrate of 50 mL/min, 30 min, fractions were collected (Fig. 1,2). Second, the cytochrome C from mix proteins was pured on preparative RP HPLC by using SynChropak C₈, the column were eluted with a gradient from 0% to 80% isopropyl alcohol, containing 0.1% TFA pH 2, at flowrate of 1.0 mL/min 15 min, fractions were collected(Fig. 3). (2) Solute-solute displacement chromatography for proteins. This study deals with of Rnase by RSA-Rnase displacement on reversed phase chromatography. The amount of displacer, volume of displacer, flowrate of column and displacement effect on the gradient elution RP HPLC with Vydac C₄(100×4.5 mm) column is discribed. The optimum displacement and high yield has been obtained.