Objectives:To investigate the pharmacokinetics (PK) and pharmacodynamics (PD)of index components of Zisu Fang preparations and additionally analysis the anti-dementia drug system characteristics.Methods:A PK-PD-drug interaction (DI) method was applied to determine the characteristics of index components of Zisu Fong preparations in vivo.Results:In the PK study,maximum plasma concentration,area under the plasma concentration-time curve,and mean residence time of index components of Zisu Fang preparations were higher in the memory-deficit model group than in the control group.This suggested that the index components of Zisu Fang preparations had an affinity for the state of dementia in this model.In the PD study,at the peak time points of anti-dementia efficacy (0.17 h and 1 h),the plasma concentrations of index components of Zisu Fang preparations reached the first or second largest plasma concentration peak or were close to the plasma concentration peak,and showed positive correlation between these two peaks,indicating that the index components of Zisu Fang synergistically exerted an anti-dementia effect.According to the association analysis of PK-PD-DI,baicalin,rosmarinic acid,salvianolic acid B,matrine,and tanshinone ⅡA were the main active ingredients of the anti-dementia drug system of Zisu Fang preparations in vivo,but were only efficacious against dementia when all five components were present at a specific concentration and proportion.Conclusions:Based on the PK and PD correlation analysis,baicalin,rosmarinic acid,salvianolic acid B,matrine,and tanshinone ⅡA are the main active ingredients of Zisu Fang preparations with regard to its anti-dementia effects,and represent the basic characteristics of drug system:natures,synergy,and affinity.