The use of chemically modified corn starch in widely accepted in the pharmaceutical and food industry. There are numerous applications of such modified products. In this investigation, corn starch, amylose and amylopectin from corn starch were cationically modified. The modified products were obtained using a quaternary ammonium salt and these cationic products were compared with their native compounds and characterized. In this study, the thermal analysis behavior of the native and modified products were investigated. The thermal degradation was carried out using a simultaneous TG-DTA unit and a DSC unit. The aim of this work was to modify these materials to render their surface cationic, and then carry out an analytical examination of the modified and the unmodified materials.