目的 考察不同采收期牛膝有机化学成分和无机元素的动态变化规律，探讨牛膝药材的最佳采收期。方法 采用高效液相色谱法（high performance liquid chromatography，HPLC）对不同采收时间牛膝中的有机化学成分进行含量测定，采用电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry，ICP-MS）对不同采收时间牛膝样品中的17种无机元素和铅、砷、镉、汞、铜等5种重金属元素进行分析，采用SPSS 20.0对结果进行含量分析及主成分分析。结果 不同采收期牛膝有机成分和无机元素呈现动态变化，综合评价显示，11月15日采收的牛膝药材综合得分最高，质量最佳。结论 综合分析认为10月底至11月中旬为牛膝的最佳采收期。

Objective To study the dynamic change rules of organic chemical composition and inorganic element in Achyranthes bidentata Bl. in different harvesting periods, and explore the optimal harvesting period of Achyranthes bidentata Bl.Method the contents of organic chemical composition in Achyranthes bidentata Bl. in different harvesting periods were determined by high performance liquid chromatography (HPLC), the contents of 17 kinds of inorganic elements and 5 kinds of heavy metals of Pb, As, Cd, Hg, Cu were determined by inductively coupled plasma mass spectrometry (ICP-MS), and content change analysis and principal component analysis (PCA) was used by SPSS 20.0.Result There were dynamic changes of organic chemical composition and inorganic element in Achyranthes bidentata Bl. in different harvesting periods and PCA results showed that the quality of samples collected in November 15 were best.Conclusion The results showed that the optimal harvesting period is the end of October to mid-November.