Abstract: From the root of Rubia schumanniana Pritz five chemical constituents including a new hydronaphthoquinonoid compound were isolated. By spectral analyses (IR, UV, MS, ¹H and ¹³C NMR) and preparation of derivatives the structure of this new compound was elucidated as 3′-carbomethoxy-4′-hydroxy-6,6-dimethylnaphtho (1′,2′-2,3) pyran, named rubimaillin. The known compounds were identified as 1-hydroxy-2-hydroxymethylanthraquinone, 1-hydroxy-2-methylanthraquinone, 1,4-dihydroxy-2-methylanthraquinoneand β-sitosterol.