This study was conducted to determine the contents of phenolic compounds and astragalosides in Astragalus membranaceus. Between the phenolic compound groups, flavonoids compounds (51.13%) had higher average concentrations than the phenolic acids groups. Among the 30 phenolic compounds, quercetin ($353.11{mu}g;g^{-1}$) provided the highest concentrations. According to different cultivation year, 3-year-cultivated Astragalus ($2612.57{mu}g;g^{-1}$) showed the highest concentrations of phenolic compounds. According to different harvest days, 6/5 harvesting Astragalus ($2615.80{mu}g;g^{-1}$) showed the highest concentrations of phenolic acids. Comparison between the top and subterranean parts of harvested Astragalus plants cultivated for 2 years, 3 years, and 5 years showed big difference of total phenolic compounds in concentrations. Further, the top part had higher amounts of the total phenolic compounds than the subterranean part among all Astragalus. This tendency was similar to those of the top root and lateral root. The concentration of the phenolic compounds in the top root was higher than that of the lateral root.