Two new phenolic acid compounds, asparoffin C (1) and asparoffin D(2), together with four known compounds, asparenyol (3), gobicusin B(4), 1-methoxy-2-hydroxy-4-[5-(4-hydroxyphenoxy)-3-penten-1-ynyl]phenol (5), and asparinin A (6), have been isolated from the stems of Asparagus officinalis. The structures were established by extensive spectroscopic methods (MS and 1D and 2D NMR). Compound 6 has obvious antitumor activities both in vitro and in vivo.