Abstract: To study the chemical constituents of Abacopteris penangiana (Hook.) Ching, various chromatographic techniques were used to isolate and purify the constituents. The structures of the obtained compounds were elucidated by spectroscopic data and physical-chemical properties. Two compounds were isolated from the n-BuOH soluble fraction of an acetone-H₂O (4∶1) extract of A. penangiana and were identified as 4′-hydroxy pneumatopterin B (I) and 6″-O-acetyl triphyllin A (II). Compounds I and II are new compounds.