To study the effect of sowing date and cultivars on grain yield of maize (Zea mays) in the early Spring sown two experiments were condueted for two seasons (2002-2003) at Agricultural Research Center of Jiroft and Kahnuj. The first, was on early mature cultrvars. Three cultivars, namly Hybrid- 320, Hybrid- 310 and Hybrid- 500 were sown at five sowing date: January 30, 10th, 20th, 30th February and March 11. The design was a split- plot replicated three times with cultivars as main plots and sowing date as sub- plots. In the second experiments, similar to the first one, instead of using early mature corn, delay mature corn has been used. It’s cultivars were (S. C 704, T. W. C 647 and 700 Karaj) The results of 2 years expriements: Showed that the first one in the best condition from cultivar of 320 hybrid with sowing date (January 30) produced 8.8 t/ha and in the second, the highest yield from Karaj 700 with sowing date of (January 30) is 12.8 t/ha, meanwhile products of cultivars are not significant for Jiroft region, delay mature cultivars with sowing date (January 30 – February 30) is recommended.