Abstract: In this study，through homology cloning and RACE strategy，a LFY homologue，named BlLFY，was isolated from a precious timber tree Betula luminifera. The full length cDNA of BlLFY was 1 305 bp with a 1 212 bp open reading frame，which encoded 403 amino acids. And，the analysis of gene structure revealed that there were two introns and three exons in genomic sequence of BlLFY，indicating same gene structure between BlLFY and LFY homologues from other plants. Multiple sequence alignment showed typical conserved N-domain and C-domain in BlLFY protein. The phylogenetic analysis showed the highest identity and close evolution relation of BlLFY to those LFY proteins from trees，such as Castanea mollissima and Juglans regia. Furthermore，expression analysis showed that the transcript of BlLFY was accumulated when plants transited to reproductive phase. Meanwhile，BlLFY gene was both detected in vegetative and reproductive organs of flowering plants，and consecutively expressed in alldevelopmental stages of male and female inflorescence. However，interestingly，the expression of BlLFY was much higher in female inflorescence than male inflorescence. These results suggested that BlLFY gene may play important roles in floral transition and development of floral organs，and may be involved in the different process of female and male inflorescences.

Key words: Betula luminifera, LFY, flowering, expression analysis