Objective: To clone the cDNA sequence of chalcone synthase (CHS) in Glycyrrhiza glabra and analyse its genetic polymorphism. Method: The cDNA sequence of CHS was cloned from root of G. glabra by reverse transcription polymerase chain reaction (RT-PCR)

then sequenced and analysed by bioinformatics software. Result: A total of 19 cDNA sequences of CHS with the full length of 1 175 bp were obtained from G. glabra samples

these 19 sequences with eighty-one polymorphic sites can be divided into 17 haplotypes

the similarity of which was 99.10%.Amino acid sequence analysis indicated that these 19 cDNA sequences encoded 14 amino acid sequences

the similarity of which was 99.34%

and 25 variable sites were determined.Bioinformatics analysis has shown that CHS was a stable hydrophilic protein

its average relative molecular weight was 42.6 kDa and isoelectric point was 5.75-6.21

it contained no signal peptides or transmembrane domains and had a conversed domain of chalcone synthase superfamily

its secondary structure mainly constituted of α-helix and random coil.The homologoue analysis showed that CHS cDNA sequence of G. glabra had the closest relationship to G. uralensis and G. inflata

and the furthest relationship to Physcomitrella patens. Conclusion: In this study

CHS cDNA sequence is successfully cloned from G. glabra samples and it shows abundant polymorphism.