The purpose of this paper is to examine the determinants of organizational structures of faculties in Japanese 4-Year colleges and universities. Numbers of samples are 241 (national sectors) and 227 faculties (private sectors). Effects of disciplinary and organizational characterictics on size of faculties, specialization to departments and status compositions of the faculties are analysed by regression analysis. Validity of "Biglan Model" is also examined in Japanese samples.
Size is determined by academic disciplines. Above all, numbers of undergraduate students is large in "Soft" and "Applied" disciplines. But, the effects of many variables on the number of faculty members are different between national and private sectors. In private institutions, "Hard-Soft" and "Pure-Applied", but in national ones "Life-Non-life" have effects on the numbers of faculty members. Specialization to departments is determined largely by disciplines. In both sectors, it is distinguished in "Hard", "Pure" and "Non-life" faculties. In national sector, status compositions of the faculties (research assiatant ratio, professor ratio and the degree of concentration of faculties' alma mater) are not more affected by disciplines than by insitutional types which date back to pri-war periods.
Biglan model is a significant model which explains the faculty structures in Japanese colleges and universities, which may imply the validity of the technological theory of organizational structures.