The purpose of this study is to examine how the fairness of selections is comprehended in arguments regarding a reform of entrance examinations for middle schools in Japan in the 1920s. This paper clarifies the problem through an analysis of discourses concerning “Lottery” as a measure for deciding enrollment. Section 1 defines the fairness of selections as a combination of equity and validity. Previous research on entrance examinations for middle schools in Japan in the 1920s are then reviewed and the significance of an analysis of discourses concerning “Lottery,” which earlier studies have rarely referred to, is explained.<BR><BR>Section 2 describes the social background to the problem of entrance examinations for middle schools in the 1920s. The reform of examinations was expected to solve three problems. These were a) to relieve childrenʼs troubles from excessive coaching, b) to ease the difficulty in entering middle schools, and c) to select suitable students according to their ability. These problems arose in the context of the increasing number of children who wanted to enter middle schools and the tendency to reconsider the former examinations.<BR><BR>Section 3 analyzes discourses on “Lottery,” which was widely recognized as an alternative to choosing applicants for middle schools. Some asserted that “Lottery” should be the only means to decide enrollment coupled with an abolition of all examinations, but this was the opinion of the minority even among supporters. The majority of supporters argued that “Lottery” ought to be performed with the condition that “obviously backward pupils” were excluded. The argument is based on a distinctive outlook on ability. According to this view, inherent differences in ability are fixed and immutable and the greater part of the people have normal ability, among which there are no significant differences. The argument is also grounded on the recognition of the difficulty of ranking people by subtle differences in ability. Therefore, “Lottery” was regarded as a superior method in term of both equity and validity. Others opposed “Lottery” from the viewpoint of social justice and educational values. These opponents of “Lottery” presupposed that ability can improve and differences in ability are variable. They were not conscious of the technical limits of artificial selections. Thus the conflict over “Lottery” did not concern values or technology but the possibility of artificial selections.<BR><BR>Section 4 examines the position of “Lottery” in the reform of entrance examinations by the Ministry of Education in 1927. In the reform, written examinations were banned in principle. Instead, the Ministry indicated a method of selection that made use of school reports, with oral and physical examinations. “Lottery” was adopted as a last resort. The reason was the technical limits of artificial selections, which were similar to the basis of supporters for “Lottery.” The recognition of the limits of artificial selections was accepted in the actual reform.<BR><BR>Section 5 presents a summary and discussion. Implications of the arguments about “Lottery” for the fairness of selections are considered.