The study used Cymbidium goeringii wild type and peloric mutant (two lateral petals mutated into lips) as experiment materials.In this research,a novel AGL6-3 gene was isolated from C.goeringii by RT-PCR and RACE-PCR techniques.Sequence analysis showed AGL6-3 gene sequences are same in the wild type and peloric mutant of C.goeringii.The gene contained an open reading frame of 720 bp encoding a putative protein of 239 amino acids.Phylogenetic tree analysis indicated that CgAGL6-3 belongs to AGL6 clade of AP1/AGL9 subfamily,named CgAGL6-3 (GenBank accession No.KU058679).Real-time quantitative PCR demonstrated that,in wild type CgAGL6-3 was highly expressed in lips,lower in dorsal sepal,lateral sepal,column,and very little in lateral petal.Whereas expression of CgAGL6-3 in peloric mutant was the highest in lip,lateral petal comes second,lower and close in dorsal sepal,lateral sepal and column.These results indicated that CgAGL6-3 play a important role in the process that lateral petals specialized into lips.