N-methylnapathalenedicarboximides (1,8-NI, 2,3-NI, and 1,2-NI) with various olefins were investigated in benzene. The reaction pathways depended largely on the structure of arene moiety of the imides. The main reactions of 1,8-NI, 2,3-NI, and 1,2-NI were found as cyclobutane formation, oxetane formation, and insertion of olefin between the C(=O)–N bond of imide moiety, respectively.