Engineering trying to apply the Taguchi method to their problems may be faced with difficulties in selecting appropriate orthogonal arrays (orthogonal main effect plans) for their purposes. In addition, little or no information is available on the alias structures of orthogonal main effect plans in general. This thesis reviews various methods of constructing orthogonal main effect plans and tabulize those with the number of runs less than or equal to 50 so that engineers may select appropriate experimental plans under various situations. In addition, this thesis explains the method of obtaining alias matrices of orthogonal main effect plans and defines two summary characteristic values to describe the alias structures concisely. These summary characteristic values are calculated for some selected basic plans.