OBJECTIVE： To study the influential factors related to efficacy of Peach kernel-Rheum palmatum couplet medicines in TCM formula， and to reveal the general regularity of compatibility environment， common ratio， processing variety and dosage forms of P. kernel-R. palmatum couplet medicines. METHODS： Using Chinese Medical Prescription Selected Dictionary edited by Peng Huairen as data source， 142 formulas of P. kernel-R. palmatum couplet medicines were collected. By establishing database， compatibility types of P. kernel-R. palmatum couplet medicines， as well as common ratio， processed prodact， dosage form were classified statistically. The influential factors related to efficacy of P. kernel-R. palmatum couplet medicines with different proportions were summarized. RESULTS： The efficacy of P. kernel-R. palmatum couplet medicines could be divided into 6 aspects and 11 roles， including activating blood circulation to dissipate blood stasis （activating blood to relieve pain， promoting blood circulation to eliminate disease， activating blood to promote menstruation， breaking stagnant and eliminating blood stasis）， eliminating carbuncle and detoxicating （cleaning intestine and clearing away the pathogenic heat of lung， eliminating carbuncle and expelling pus， eliminating sore and detoxicating）， expelling the pathogenic heat to loosen the bowels， warming yang for dispelling cold， fortifying the spleen and nourishing the stomach， relaxing tendon and activating blood. The compatibility environment of P. kernel-R. palmatum couplet medicines were mainly compatible with TCM for activating qi to eliminate stasis， activating blood to promote menstruation， breaking stagnant and eliminating blood stasis， expelling the pathogenic heat to expel stasis. The ratio of P. kernel to R. palmatum ranged 1 ∶ 8-4 ∶ 1， and the ratio ranged 1 ∶ 8-3 ∶ 1 when performing the role of actirating blood circalation to dissipate blood stasis. Common processed products were crude P. kernel and prepared R. palmatum. Common dosage forms were mainly decoction， pill and powder. CONCLUSIONS： Compatibility environment， ratio， processing varieties， dosage forms influence the effects of P. kernel-R. palmatum couplet medicines， especially compatibility environment.