Abstract: In order to establish a reverse transcription loop-mediated isothermal amplification (RT-LAMP) method to detect the sweet potato feathery mottle virus (SPFMV)and sweet potato chlorotic stunt virus (SPCSV), improve the detection sensitivity and realize the visualization of the results, four RT-LAMP specific primers were designed according to the nucleotide sequences of SPFMV coat protein gene (CP) and SPCSV heat shock protein gene (Hsp 70) in this study, and then the single factor optimization experiment was used to optimize the multiple factors in the RT-LAMP reaction system including time, temperature, BST polymerase, Mg²⁺, RNase inhibitor, dNTPs and Betaine concentration, with the constant temperature amplification for 60 min. Through the agarose gel electrophoresis analysis, and the SYBR Green I visual color development, the results showed that: the optimal reaction system of SPFMV was as follows: FIP/BIP 2 μL, F3/B3 0.5 μL, BST polymerase 1.0 μL, dNTPs 0.6 μL, MgSO₄ 1.5 μL, RNase inhibitor 1.0 μL, Betaine 7 μL, at 62℃ for 60 min. The optimal reaction system of SPCSV was as follows: FIP/BIP 2 μL, F3/B3 0.5 μL, BST polymerase 1.0 μL, dNTPs 0.6 μL, MgSO₄ 1.5 μL, RNase inhibitor 1.2 μL, Betaine 7 μL, at 64℃ for 60 min. The four fragments of the whole genome of SPFMV (SPFMV-1, SPFMV-2, SPFMV-3, and SPFMV-4), SPCSV-Hsp 70 and RGNNV were used to test the specificity. Then ,the specific RT-LAMP detection methods of SPFMV and SPCSV were established respectively, and the typical waterfall-like bands with RT-LAMP were amplified, which were consistent with the results of gel electrophoresis and SYBR Green I coloration. The lower limits of sensitivity detection of SPFMV and SPCSV were as follows: 1×10^-6 and 1×10^-3 ng·μL^-1. The detection sensitivity of this method was high, and the results could be visualized. Field sweet potato seedlings and in vitro tissue culture sweet potato seedlings were tested, and the success rate of SPFMV-RT-LAMP detection method was 100%. The success rate of SPCSV-RT-LAMP detection method was 95%, indicating that the developed RT-LAMP detection method of SPFMV and SPCSV was suitable for the rapid detection of SPFMV and SPCSV.