Abstract: Objective To investigate the method of isolation and purification of collagen from Pseudosciaena polyactis scales with acetic buffer. Methods The preparation of collagen from Pseudosciaena polyactis scales mainly contained the following steps; washing scales with cool water to delete impurity; precipitating Ca2+ soaked by the EDTA buffer; extracting the collagen with acetic buffer; and dialyzing for purification. The purity of collagen was determined by SDS-PAGE and differential scanning cycler (DSC) was used to analyze the thermodynamic character. Results The optimum conditions in this technology were that extracted temperature should be controlled below 10℃, concentration of the EDTA and acetic buffer were both 0.5 mol/L, and molecular weight over 100 000 were prevented by the dialysis-membrane. The prepared collagen showed three clear bands by SDS-PAGE, the molecular weights were 114 000, 124 000 and 200 000, respectively, the thermal denatured temperature was 37. 7℃. Conclusions The isolated collagen from Pseudosciaena polyactis scales could be applied in the field demanding for higher quality.