The adsorption of cytochrome c onto mesoporous silica (MCM-41) was investigated in this study. MCM-41 was synthesized and characterized by different methods. The pore size of MCM-41 was calculated from each method and all were in agreement with each other. Result from SAXS method showed a well ordered 2D hexagonal structure of MCM- 41. To investigate the effect of pH on adsorption process, different buffers were used with various pH in the range from 3.8 to 10.7. It was observed that the maximum adsorption occurs at pH near the isoelectric point of cytochrome c. The surface charges of cytochrome c and MCM-41 play an essential role for the process of adsorption. Desorption of cytochrome c from MCM-41 was investigated as well. Pure water and buffers with pH 7.1 and 10.7 were used to study the desorption. The result shows that desorption of cytochrome c from MCM-41 takes place at a pH above its isoelectric point.