Objective: To analyze main active compositions of drug-containing medium composed by monascus and Polygoni Multiflori Radix after fermentation and optimize its fermentation technology. Method: Qualitative and quantitative analysis were established by UV-visible full wavelength scanning method and ultraviolet spectrophotometry

based on single factor tests

with yields of monacolin K

free-anthraquinone

stilbene glucoside and combined-anthraquinone as indexes

orthogonal test was adopted to investigate effects of fermentation time

amounts of monascus and Polygoni Multiflori Radix on fermentation technology. Result: Contents of stilbene glucoside

combined-anthraquinone and total anthraquinone showed a downward trend

but free-anthraquinone showed a upward trend.Optimum fermentation conditions were as follows:Polygoni Multiflori Radix amount of 5%

fermentation temperature at 28 ℃

monascus amount of 6%

fermentation time of 7 d.Yields of stilbene glucoside

combined-anthraquinone

free-anthraquinone and monacolin K were 37.84

0.89

1.54

0.41 mg·g-1

respectively. Conclusion: Polygoni Multiflori Radix has a promoting process on growth of monascus and its secondary metabolites of monacolin K

but monascus reduces the content of combined-anthraquinone in Polygoni Multiflori Radix

which improves medicinal value of Polygoni Multiflori Radix.