Potato, wheat, maize and oat starches were modified by physical, chemical and enzymatic treatment. The obtained preparations were characterized in terms of specific surface area, volume of mesopores and their average diameter with ASAP 2000 apparatus, by method of low-temperature adsorption of nitrogen. Changes in the properties of starch granules due to the applied modifications were observed. It was proved, that enzymatic modification had the highest influence on porosity. Among the oc-amylase modified preparations, the highest increase of porosity occurred in oat and wheat starch, lower in maize and the lowest in potato starch. The above results were confirmed by granules morphology analysis performed by means of scanning microscopy.