The root wood of Austroplenckia populnea var. ovata was extracted successively with chloroform and methanol. Lapachol and dehydro-beta-lapachone were isolated from the chloroform extract, and euonine, alatusinine, wilfordine, 2-O-deacetyleuonine (1), 7-O-deacetyleuonine (2), and austronine (3) from the methanol extract. The structures of the new compounds 1-3 were elucidated by spectroscopic data interpretation. Lapachol, dehydro-beta-lapachone, euonine, alatusinine, and wilfordine are known compounds that are newly identified from root wood of Austroplenckia populnea.