Background:Danshen (Salvia miltiorrhiza, DS) and Honghua (Carthamus tinctorius, HH) are commonly usedtraditional Chinese medicines for activating blood and removing stasis, and DS-HH (DH) herbal pair had po-tential synergistic effects on promoting blood circulation. Therefore, it is essential to make clear the activecomponents of this herbal pair for better understanding their potential synergistic effects.Purpose:To comprehensively evaluate the activity of DH herbal pair on physiological coagulation system of rats,and seek their potential active components by spectrum-effect relationship analysis.Methods:The water extracts of DH herbal pair with different proportions (DS: HH = 1:1, 2:1, 3:1, 5:1, 1:5 and1:3) were prepared. Male Sprague-Dawley rats were randomly divided into eight groups: blank group, modelgroup, model + 1:1 (DH) group, model + 2:1 group, model + 3:1 group, model + 5:1 group, model + 1:5 groupand model + 1:3 group. The intragastric administration was performed for eight times with 12 h intervals. SC40semi-automatic coagulation analyzer was employed to determine coagulation indices. Meanwhile, HPLC and LC-MS were applied for chemical analyses of DH extracts. Finally, the active ingredients were screened by spectrum-effect relationship analysis and the activities of major predicted compounds were validatedin vitro.Results:Different proportions of DH extracts could significantly prolong thrombin time (TT) and activatedpartial thromboplastin time (APTT), increase prothrombin time (PT) and decreasefibrinogen (FIB) content,reduced whole blood viscosity (WBV) and plasma viscosity (PV), decreased erythrocyte sedimentation rate blood(ESR) compared with model group. Furthermore,fifteen highly related components were screened out by thespectrum-effect relationship and LC-MS analysis, of which caffeic acid, salvianolic acid B, hydroxysafflor yellowA and lithospermate acid had significant blood-activing effect by prolong APTT and decrease FIB content at high(0.6 mM), medium (0.3 mM) and low (0.15 mM) (except lithospermate acid) concentrationsin vitro.Conclusions:DH herbal pair showed strong blood-activating effect on blood stasis rat through regulating theparameters involved in haemorheology and plasma coagulation system. Four active compounds, caffeic acid,salvianolic acid B, hydroxysafflor yellow A and lithospermate acid predicted by spectrum-effect relationshipanalysis had good blood-activating effect. Therefore, spectrum-effect relationship analysis is an effective ap-proach for seeking active components in herbal pairs.