The purpose of this research is to consider theoretical points of view on a preceding research related to an engineering design and abstract the definition of engineering design ability, its subdivision and element on the basis of experts' recognition. To achieve this goal, various literature researches were carried out by examining domestic and foreign articles in journals, lots of dissertations, and books related to engineering design through theoretical consideration. And to secure the validity on the definition of engineering design ability, its subdivision and element through the theoretical study, a feasibility evaluation method by the experts was applied. And the feasibility evaluation of the experts was conducted through 2 stages. The major conclusions of this study are as follows. Firstly, based on the experts' recognition on the definition of engineering design ability, its subdivision and element, which were revised through the 1st feasibility evaluation and then utilized in the 2st one, the validity was confirmed, and the subdivisions of the engineering design ability were divided into 5 and the elements of the subdivision ability were 33. Secondly, the engineering design ability was defined as "the one to design a realizable product with consumers' demand fully satisfying, based on a knowledge application ability, thinking ability, communication ability, problem-solving ability, and teamwork ability to solve engineering problems." Thirdly, the subdivisions of the engineering design ability were divided as a knowledge application ability, thinking ability, communication ability, problem-solving ability, and teamwork ability.