Important physiological and biochemical changes in corn seeds submitted to high drying temperatures have been studied. The objective of this research was to evaluate the effect of high drying temperature on electrophorectic patterns of the -amylase enzyme in corn seed lines of simple hybrids and respective reciprocals. The seeds were harvest with approximately 35% water content and dried at 45C. The physiological quality of seeds from each material was evaluated by the germination test and the -amylase enzyme was extracted from germinated seeds in Tris ? HCl 0, 2 M buffer. Seeds of lines dried in the shade were utilized as control. The enzyme profiles of -amylase showed great band intensity for tolerance to high drying temperature lines and hybrids. For lines tolerant to high drying temperature there were hardly any differences in enzyme activity for shade-dried seeds or artificially dried seeds, unlike the intolerant lines, in which more activity was verified in naturally dried seeds. Hybrids seeds and respective reciprocal hybrids presented differences in the activity -amylase enzyme.