Abstract: Earlier research results showed that rice auxin efflux protein OsPIN1a probably participated in regulating negative phototropism of rice roots. To explore the relationship between other OsPIN genes and negative phototropism of rice roots， gene-specific primers were used to amplify OsPIN1b gene by RT-PCR based on the OsPIN1b sequence in GenBank. Sequencing result showed that the full ORF was obtained（1 665 bp）. Bioinformation analysis showed that the sequence was 100% identity with the reported sequence， the GC content of OsPIN1b ORF was 64.08% and OsPIN1b encoded 554 amino acid residues. The OsPIN1b-green fluorescent protein （gfp）fusion expression vector pCAMBIA-1301-OsPIN1b∷GFP was constructed and transformed into Japonica rice Zhonghua11 by Agrobacterium tumefaciens. Molecular detection and GUS assay showed that the target construct was integrated into the genome of rice， which laid the foundation for further study of the function of OsPIN1b in regulating negative phototropism of rice roots.