In this study, the enhanced green fluorescent protein(EGFP) was combined with auxin polar transporter PIN1 and made it fluorescently labeled. The effects of PIN1 on auxin polar transport and cell elongation growth were studied in tobacco trichome. The fusion label gene EGFP-PIN1 was recombined under the promoter of the trichome specific expression gene GL2 from Arabidopsis thaliana to enable it specific expression in the transgenic. The recombinant GL2pro::EGFP-PIN1 was constructed in the Ti plasmid pEGAD and then transformed into tobacco WS38 by Agrobacterium tumefaciens mediated leaf disc co-culture transformation. Several transgenic tobacco plantlets were screened out and identified. The fluorescence observation of these transgenic tobacco trichome showed that the labeled green fluorescence signals appeared in the interval area of the trichome cells with an obvious polarity distribution. It enables the polarity transport of auxin in trichrome cells and forms a polarity distribution of axuin. After treatment with the auxin polar transport inhibitor triiodobenzoic acid (TIBA), the elongation growth of trichome was significantly inhibited and the polarity distribution of fluorescence in cells was also weakened. Thus, we conclude that the polarity distribution of auxin in tobacco trichome plays a key role in the elongation of tobacco trichome. Inhibition of auxin polar transport not only inhibited cell elongation of trichome, but also affected the polarity distribution of auxin polar transport protein PIN.