Sweet corn breeders use combining ability assessment as a key tool to identify the best inbred lines and hybrids. Using the line × tester mating scheme, ten new inbred lines were crossed with two testers at Sakha Agricultural Research Station in 2022 summer season. The resulting 20 crosses were planted in a randomized complete block design with three replications on two planting dates, 20 April and 20 June at Sakha Agricultural Research Station in 2023 summer season. Combined analysis of variance for eight traits across two planting dates showed highly significant differences between two planting dates for the studied traits. The early planting date on 20 April showed highest values for all studied traits compared with the late one. Additive gene effects were more vital in controlling the inheritance of days to 50% silking, fresh yield with husk, fresh yield without husk, ear length, number of rows/ear and number of kernels/row, while non-additive gene effects were preponderance in the inheritance of plant height and sweetness. The desirable inbred lines for GCA effects were Sk5006/2 and Sk6021/8 for most studied traits. Hybrids Sk5006\2 × Sk5008/1, Sk5005/9 × Sk5008/1 and Sk5006/2 × SC super sweet 110 showed high sweetness and high fresh yield without husk. These hybrids could be used for commercial production, after testing in advanced trials.