A novel L-galactono-1,4-lactone dehydrogenase gene LbGLDH was isolated from Lycium barbarum in Qinghai by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE).The full-length cDNA of LbGLDH was 2 114 bp,and contained a complete open reading frame (ORF) of 588 amino acid residues and 5′-end 57 bp and 3′-end 290 bp.Homology analysis indicated that LbGLDH gene sequence was highly 88%-90% to GLDH from Solanum lycopersicum,Solanum tuberosum,Nicotiana tabacum.LbGLDH encoding amino acid sequence contained GLDH protease with FAD-binding-4 and ALO domain structures.Real time-PCR analysis indicated that the expression of LbGLDH gene,ascorbic acid content and GLDH activity were all the strongest in the flower and fruit,and the least in mature-leaf.It was speculated that LbGLDH gene expression could promote accumulation of the ascorbic acid in L.barbarum fruits.