Objective: The dynamic changes of composition and efficacy were analyzed during the process of preparation of Scutellariae Radix extract(SRE)

and the research ideas to determine the reasonable extraction process were explored. Method: Four products were prepared according to the preparation procedure of SRE collected in the 2015 edition of Chinese Pharmacopoeia

which were water extract(sample 1)

first acid precipitation product(sample 2)

alcohol precipitation product(sample 3) and second acid precipitation product(sample 4).The content of each component in the above four samples and their antipyretic and anti-inflammatory effects were determined

respectively.The correlation between composition and efficacy were analyzed by grey correlation analysis and bivariate correlation analysis. Result: Acid precipitation could significantly increase the content of five flavonoids in SRE

but alcohol precipitation was not obvious to improve the content of five flavonoids.Sample 1 had the strongest antipyretic effect on the fever induced by dry yeast in rats

the inhibitory effect of sample 2 on dimethylbenzene-induced mouse ear swelling and carrageenan-induced foot swelling was the most obvious.The antipyretic and anti-inflammatory effects of sample 3 and 4 obtained by further purification were weakened

which meant further purification caused loss of efficacy.The gray correlation coefficients between baicalin and temperature increase

ear swelling rate and foot swelling rate were 0.78

0.81 and 0.70

the bivariate correlation coefficients were 0.957

0.848 and 0.819

respectively;which were all maximum among the five components

indicated that baicalin had the greatest impact on efficacy.In addition to baicalin

the bivariate correlation coefficients between other four components and temperature increase

ear swelling rate and foot swelling rate were negative(except for baicalein in antipyretic effect)

which indicated that the overall antipyretic and anti-inflammatory activity for SRE can be enhanced by increasing the content of these four components. Conclusion: In summary

although baicalin has the greatest impact on the efficacy of SRE

but not the higher the better;on the contrary

the overall antipyretic anti-inflammatory effect of SRE can be enhanced due to the addition of other four components.The antipyretic and anti-inflammatory effect of SRE is a contribution of a variety of ingredients.During the preparation of SRE

we should take into account the impact of a variety of ingredients on the efficacy

in order to void loss of efficacy due to over-purification.