Six quinoline alkaloids have been newly isolated from a n-hexane extract of Orixa japonica stems. Four alkaloids (pteleprenine, N-demethyllunidonine, N-methylflindersine and 8-methoxy-N-methylflindersine) are described for the first time in this species. Isopteleprenine was obtained as a natural product for the first time; (+)-isoptelefolidine is a new compound. Unambiguous H-1 and C-13 NMR assignments of pteleprenine and isopteleprenine have been achieved.