The present investigation has been undertaken in sweet corn to carry out the combining ability analysis and to estimate heterosis of yield and yield contributing characters. Eight divergent parents were selected and crossed in diallel fashion excluding reciprocals during kharif, 2010. The resulting 28 crosses along with parents and a standard check Sugar 75 and Madhuri were evaluated in Randomized Block Design replicated thrice, during rabi, 2010-11 at Agricultural Research Institute, Rajendranagar, Hyderabad. The data were collected on plant height, ear height, ear length, ear girth, number of kernel rows per ear, number of kernels per row, green cob yield, 100 kernel (dry) weight and seed yield (wet) per plant. Estimates of heterosis, heterobeltiosis and standard heterosis were variable among crosses in desirable direction and some of them turned out to be best specific crosses. The cross combinations 6127 x 6100 (20.09%) and 6104 x 6100 (19.65%) for seed yield (wet) per plant were found to be superior to the standard check Madhuri and can be considered as high heterotic and can be used as single cross hybrids after evaluation in multi-location trials.