Sweet corn (Zea mays L.Saccharata) is one of the most popular vegetable in the world. This experiment was carried out in the agricultural and natural resources research center of Khorasan-Razavi, Mashhad, Iran during 2013-2014. A randomized complete block design with three replications was conducted in order to investigate the heritability of sweet and super sweet corn quantitative characteristics in 37 sweet corn inbred lines and hybrids. The genotypes were consisted of 13 inbred lines, 17 promising hybrids and 7 new commercial sweet and super sweet corn varietal. Plant height, ear length, ear diameter, kernel depth, row per ear, kernel per row and kernel yield was measured. Heterosis evaluated by combining parental data. Analysis of variance showed that there were significant differences between all studied genotypes except plant height, ear length, kernel depth, kernel number per eat, row per ear and kernel yield. Genetic diversity resulted in variation between hybrids and inbred lines.The highest and lowest conservable grain yield produced by Passion (12.5 ton/ha) and Harvest gold (0.32 ton/ha) respectively. Broad sense heritability ranged between 64% and 85%, for kernel depth and kernel yield, respectively. Results showed that hybrids which one of their parental line was Chase, Basin or temptation produced higher yield, kernel depth, kernel per row, row per ear and plant height than the other genotypes.