Investigation of the root bark of Magnolia kachirachirai led to the isolation of a new sesquiterpene, kachirachirain (1), and a new aporphine alkaloid, kachirachiranine (2), together with 20 known compounds, of which dimethyl 4,4'-methylenebis(4,1-phenylene)diurethane (3) was isolated for the first time from a natural source. Their structures were elucidated by spectroscopic analysis.