Tissue culture plantlets of Paeonia ostii “Fengdan”were used as material and inoculated in the basal medium containing 0 - 5.0 mg/L silver nitrate. By measuring the total phenols content,types and content of free phenol and the expression of related genes,the inhibition effects of different concentrations of silver nitrate on callus browning were determined. The results showed that adding silver nitrate in medium inhibited the expressions of related genes,significantly reduced the content of polyphenols in the callus and subsequently reduced browning,of which the comprehensive results by 2.0 mg/L was the best. The main phenols contributing callus browning were chlorogenic acid,rutin,coumaric acid,p-coumaric acid,epicatechin,and dihydro quercetin. In silver nitrate-treated callus,there were significant correlations between the expressions of transcription factors MYB2,WD40-1,and WD40-2,the structural gene phenylalanine ammonia lyase(PAL),flavanone reductase(DFR),chalcone synthase(CHS),chalcone isomerase(CHI),3-dihydroflavonol hydroxylase(F3H),flavonol 3'-hydroxylase(F3'H)and browning grade as well as total phenols content(P < 0.05).