The pharmacokinetics of the main components of protocatechualdehyde, salvianolic acid B, tanshinone II(A), cryptotanshinone, and the hydrophilic or lipophilic extracts of Salvia Miltiorrhiza Bge., in rat plasma were studied after oral administration separately to explore the interactions between them. Some components in the hydrophilic extract depress the absorption of the protocatechualdehyde, on the contrary, enhance the absorption of the salvianolic acid B and depress its elimination rate. The concomitant components in the lipophilic extract might enhance the absorption of cryptotanshinone and its distribution from the centre compartment to the peripheral compartment, and the metabolism to tanshinone II(A). The 'concomitant components' in the extract of Chinese material medica had significant effect on the pharmacokinetics of its 'marker components'. It can not only be rival, synergic, but also have the effects on metabolism. Therefore the traditional Chinese medicine was a complicated system, It should be taken a scientific and dialectic view in the research and development processes.