The impacts of climate change on agriculture sector are divided into two factors, namely crisis and opportunity factor. The crisis factor is such as more frequent and more intense disaster. On the other hand, there are also opportunity factors such as extension of crop cultivation period. Godangok and Guseulok were sown at 30 June, 10, 20, 25, 30 July and 5 August in 2011, 2012. It takes about 22 ~ 23 days from silking to harvest when sweet corn hybrids were sown in 30 June, but 25 July-sowing takes 27 ~ 30 days and 8 August-sowing takes 30 ~ 36 days. The accumulated temperature for harvesting of sweet corn was about 1,600 ~ 1,900˚C. The minimum cumulative temperature from seeding to harvest was approximately 520 ~ 590˚C. The growing degree days (GDD) from seeding to harvesting were approximately 213 ~ 353˚C and it was highest in the last sowing. At sowing in 2011 (916 ~ 1,067˚C) and 2012 (911 ~ 1,055˚C) all showed no significant difference to the harvest GDD. Plant height, ear height, stem diameter, and dry matter weight were reduced as planting date was delayed (p < 0.05). Ear weight in Godangok was 715 kg per 10a and in Guseulok was 677 kg per 10a, respectively in two years. The aim of the present study was to investigate the growth and yield of sweet corns during ripening according to the sowing time, and to provide information necessary to improve the quality of sweet corns.