This research is concerned with studying the response of four corn hybrids, two yellow and two white represent the single and three-way hybrids to splitting nitrogen.  The study was carried out in Assiut University Experimental Farm during 2008 and 2009 seasons.  The design of the experiment was split plot in which the hybrids was in the main plots and splitting nitrogen in the sub plots.
The results obtained proved that the single cross hybrids surpassed the three-way ones in both vegetative attributes and grain yield & its components in the two growing seasons.  Partitioning nitrogen into four doses favoured vegetative & yield attributes.  All involved interactions between nitrogen x hybrids were significant indicating that the three-way hybrids showed  considerable responses to nitrogen splitting treatments as compared with the single ones