A 966 bp fragment of phloem protein 2(PP2) gene in the promoter region of Cucurbita maxima was amplified by PCR.The fragment was cloned into pUCm-T vector,and a new recombined vector named pUCm-PSP was obtained.A new plant expression vector named pHZ03 in which the reporter gene GFP is droved by PSP was constructed after cutting two vectors pUCm-PSP and pCAMBIA1302 with restriction enzymes,subsequently recovering,ligation,transformation and identification.The recombined plant expression vector was transferred into Agrobacterium tumefaciens strains of LBA4404,GV3101,EHA105 and A.rhizogenes strain of Ri15834 by using cell competent method.