Maize (Zea mays L.) is one of the most important cereal crops in the world and ranks the third of most important cereal crops in the world. Also, it ranks the third of the world cereal crops which surpassed by wheat and rice. In the USA maize is considered the king of cereal crops. Diallel cross design is widely and extensively used for estimating the types of gene action. Several methods have been devised in this respect to estimate the genetic components in plant population, few information, however is available about comparing and relative efficiency of these methods. The analyses of methods of diallel cross in the present investigation were chosen because they are widely used and applied simulantaneously to the same basic population with one restriction that the number of crosses, including selves, in each should be the same. Thus the methods of analysis can be compared on the basis of their return in terms of information yielded. Our objectives were (1) to establish the magnitude of both general combining ability GCA and specific combining ability SCA effects and their interaction with the two sowing dates. (2) To make a comparison between common methods of genetic analysis methods.