Abstract: This paper studied the mechanism of inhibition of primary root growth and lateral root development regulated by rabdosinate using polar auxin carriers reporter lines(PIN1::PIN1:GFP,PIN3::PIN3:GFP,PIN4::PIN4:GFP) and auxin reporters line(DR5::DR5:GFP). The results showed that the length of primary root and the number of lateral root in wild-type Arabidopsis thaliana seedlings were significantly reduced by 60~80 μmol·L^-1 rabdosinate. However, the mutants pin1, pin3 and pin4 showed a lower level of sensitivity to rabdosinate in terms of the inhibition of root elongation and lateral root formation compared with the WT seedlings.Rabdosinate(60~80 μmol·L^-1)induced a dose-dependent increase in DR5 activity and the abundance of PIN1-GFP fusion proteins in the root tips of A.thaliana, and significantly decreased the abundance of PIN3-GFP and PIN4-GFP at their respective cellular locations. These results suggest that rabdosinate may promote acropetal auxin transport activities by increasing the abundance of PIN1 and block transverse auxin transport activities by decreasing the abundance of PIN3-GFP and PIN4-GFP, resulting in auxin accumulation in the root meristematic cells and the inhibition of root growth and lateral root development.