In order to analyze the function of CreA,a carbon metabolism regulator of Penicillium italicum,which is a postharvest pathogen of citrus fruits，the PicreA gene was successfully cloned.The gene has 1 236 bp cDNA length without intron,which encodes 411 amino acids and contains two typicalzinc finger domains of transcription factors.Phylogenetic tree analysis showed that the PiCreA protein had the highest homology with Penicillium expansum.Transcriptional analysis of PicreA revealed a complex express profile in response to different carbon sources.For monosaccharide,higher expression was induced in a short period of time.With the prolongation of time,in the case of repressing carbon source such as glucose,PicreA expression showed a gradual decline and then increased.It was presumed that selfinhibition of PicreA occurred.In term of the depressing carbon source like xylose,PicreA expression level lightly decreased and gradually remained fairly high.For nonmonosaccharide carbon source such as ethanol,high level of PicreA expression was maintained.The PicreA gene is stably expressed throughout the infection process of Penicillium italicum on citrus fruits.