The volatile chemical components of herb pair Rhizoma Ligustici Chuanxiong-Radix Paeoniae Rubra (RLC-RPR) were analyzed by gas chromatography-mass spectrometry( GC-MS), chemometric resolution method (CRM), and overall volume integration methods. By using these methods upon two-dimensional data, 52, 33, and 61 volatile chemical components in the essential oil of RLC, RPR, and herb pair RLC-RPR were, respectively, determined qualitatively and quantitatively, accounting for 95. 14%, 95. 82% and 90.18% of the total contents of the essential oil of RLC, RPR and herb pair RLC-RPR, respectively. The experimental results show that the volatile chemical components of herb pair RLC-RPR in number are almost the addition of that of two single drugs RLC and RPR, but are changed in contents.