For the purpose of testing the hypothesized major contribution of vertical exchange quality to management development, 1058 line managers at four different hierarchical levels were sampled from five of the leading corporations in Japan. Hierarchical regrssion and path analysis results showed that both vertical exchange quality and the present hierarchical level contributed uniquely to managers' career development activities after the contributions of company, age, tenure, education, technical specialty and intrafirm mobility were controlled. In addition, the contributions of these control variables were estimated and a summary path diagram was presented. Implications of these findings for our understanding of Japanese management development were discussed, focusing upon the two dominant management career paths in Japanese organizations: one through the traditional nenko system and the other through the interpersonal (leader-member relations) path.