Abstract: To understand the genetic and molecular mechanisms of floral development in Populus tomentosa，a fulllength cDNA sequence of PtPCPlike gene was isolated from a male floral bud cDNA library of P.tomentosa，with the method of bacteriophage absorption by filter paperPCR.The sequencing results indicated that the 595 bp sequence contained a complete open reading frame, which encoded 91 amino acid residuals. BLAST analysis revealed that the gene had a similar sequence domain with Arabidopsis pollen coat protein genes, therefore it was named as PtPCPlike.RTPCR showed that PtPCPlike had higher expression abundance in male poplar floral buds and roots, and a lower abundance in female floral buds. A plant expression vector carrying 35S∶∶PtPCPlike was constructed and transformed into tobacco and poplar via Agrobacterium mediated method, a batch of positive transformation plants were obtained. Expression pattern of PtPCPlike in different tobacco lines was examined using qRTPCR. Results showed that PtPCPlike was expressed higher in all transgenic lines than in wide type, and significant expression differences were seen among different transgenic lines.