Fourier Transform Infrared spectroscopy (FT-IR) is a effective experimental techniques for the analysis of secondary structure of polypeptides and proteins in aqueous solution.To obtain high-quality FT-IR spectrum of proteins in aqueous solution, high concentration of protein (>10 mg/ml) are needed.In this study, we developed a new FT-IR method by absorbing proteins onto aluminum hydroxide gel.The results reveal that only 0.5 mg/ml proteins are needed for collecting effective FT-IR spectrum, and lowers the concentration requirement by at least 20-fold as compared with the conventional FTIR method.The new method permits FTIR study of proteins to be carried out in the same concentration range as is used for circular dichroism and fluorescence spectroscopy.The technique making it possible to study concentration-dependent conformational changes of protein and directly cross-reference among three commonly used techniques in protein studies.