The Arabidopsis AINTEGUMENTA (ANT) gene, which encodes an APETALA2 (AP2)-like transcription factor, controls plant organ cell number and organ size throughout shoot development. ANT is thus a key factor in plant shoot development. Here, we found that ANT plays an essential role in conferring salt tolerance in Arabidopsis. ant--Knock Out (KO) mutants presented a salt-tolerant phenotype, whereas 35S:ANT transgenic plants exhibited more sensitive phenotypes under high salt stress. Further analysis indicated ANT functioned mainly in the shoot response to salt toxicity. Target gene analysis revealed that ANT bound to the promoter of SOS3-LIKE CALCIUM BINDING PROTEIN8 (SCABP8), which encodes a putative calcium sensor, thereby inhibiting SCABP8 expression. It has been reported that the salt sensitivity of scabp8 is more prominent in shoot tissues. Genetic experiments indicated that the mutation of SCABP8 suppresses the ant-KO salt-tolerant phenotype, implying that ANT functions as a negative transcriptional regulator of SCABP8 upon salt stress. Together, the above results reveal that ANT is a novel regulator of salt stress, and that ANT binds to the SCABP8 promoter, mediating salt tolerance.