Abstract: 【Objective】 This study aimed to screen cassava interacting proteins of the salicylic acid （SA） receptor MeNPR4，and the disease-resistant functions were analyzed，thereby providing scientific basis for exploring the defense mechanism mediated by the interaction between MeNPR4 and other hormones as well as genetic improvement and bree-ding of cassava. 【Method】 Taking the MeNPR4 gene cloned using cDNA from leaves of cassava variety Hunan 124 as a template， the yeast two-hybrid （Y2H） system was used to screen the candidate interacting proteins of MeNPR4，and bimolecular fluorescence complementation （BiFC） assays were used for validation. The fusion expression vector pCAMBIA2300-MeERS2-GFP was constructed for subcellular localization of the ethylene （ET） receptor MeERS2. The silenced plants of MeERS2 gene were inoculated with the infectious clone of cassava common mosaic virus （CsCMV），and the CsCMV accumulation was determined via real-time fluorescence quantitative PCR. The chlorophyll fluorescence imaging system was employed to analyze the disease-resistant functions of silenced plants. 【Result】 The MeNPR4 gene was cloned from cassava， and its length was 1698 bp， which was consistent with the reference sequence （Manes.14G155900） in the Phytozome database. A bait expression vector pGBKT7-MeNPR4 was constructed， and 63 candidate interacting proteins were screened by Y2H test， confirming a direct in vitro interaction between MeERS2 and MeNPR4. For BiFC assay，the MeNPR4 and MeERS2 were individually cloned into bimolecular fluorescence complementation vectors pFGC-cYFP and pFGC-nYFP，and the results indicated a direct in vivo interaction between MeERS4 and MeNPR2. Subcellular localization analysis revealed that the MeERS2 protein localized at the nucleus and cytoplasm. A MeERS2-specific fragment was ligated into the pTRV2 vector to generate silencing plants. Real-time quantitative PCR analysis of cassava leaves injected with the CsCMV infectious clone revealed that the CsCMV accumulation in the two silenced plants was significantly higher than that in the control （P<0.05， the same below）， and it gradually increased over time. The maximum photochemical efficiency （F_v/F_m）， actual photochemical efficiency Y（II），and photochemical quenching coefficient （qP） of silenced plants were significantly lower than those in control， but non-regulated energy dissipation Y（NO） of silenced plants was higher than this in control. Silenced plants exhibited more pronounced leaf etiolation than the control. 【Conclusion】 The SA receptor MeNPR4 interacts with the ET receptor MeERS2，and the MeERS2 gene positively regulates the immune response of cassava to common mosaic disease.