The mitogen-activated protein kinase kinase kinase 18 (MAPKKK18) has been reported to play a role in abiotic stress priming in long-term abscisic acid (ABA) response including drought tolerance and leaf senescence. However, the upstream transcriptional regulators ofMAPKKK18remain to be determined. Here, we report ABA-responsive element binding factors (ABFs) as upstream transcription factors ofMAPKKK18expression. Mutants ofabf2,abf3,abf4, andabf2abf3abf4dramatically reduced the transcription ofMAPKKK18. Our electrophoresis mobility shift assay and dual-luciferase reporter assay demonstrated that ABF2, ABF3, and ABF4 bound to ABA-responsive elementcis-elements within the promoter ofMAPKKK18to transactivate its expression. Furthermore, enrichments of the promoter region ofMAPKKK18by ABF2, ABF3, and ABF4 were confirmed byin vivochromatin immunoprecipitation coupled with quantitative PCR. In addition, we found that mutants ofmapkkk18exhibited obvious delayed leaf senescence. Moreover, a genetic study showed that overexpression ofABF2,ABF3, andABF4in the background ofmapkkk18mostly phenocopied the stay-green phenotype ofmapkkk18and, expression levels of five target genes of ABFs, that is,NYE1,NYE2,NYC1,PAO, andSAG29, were attenuated as a result ofMAPKKK18mutation. These findings demonstrate that ABF2, ABF3, and ABF4 act as transcription regulators ofMAPKKK18and also suggest that, at least in part, ABA acts in priming leaf senescenceviaABF-induced expression ofMAPKKK18.