In order to explore the dwarf gene and analyze the dwarfing mechanism in maize， the maize dwarf mutant K718d， wild-type K718 and their F₂ segregation population were used for gene mapping by BSA whole genome resequencing （BSA-reseq） and transcriptome sequencing （RNA-seq）. Three candidate regions with a total length of 21.03 Mb hosting 438 annotated genes were detected on chromosome 1. A total of 2374 differentially expressed genes （DEGs） were identified， including 1452 up-regulated genes and 922 down-regulated genes. KEGG analysis showed that DEGs were mainly involved in metabolic pathways including phenylpropane metabolism， fatty acid chain elongation and galactose metabolism. Gene function annotations showed that DEGs were involved in cell growth， cell wall composition， and plant hormone anabolism. BSA-reseq and RNA-seq suggested 26 candidate genes， of which 19 were found with non-synonymous mutations. Two candidate genes Zm00001d032035 and Zm00001d032422， which are annotated with plant hormone metabolism， were obtained based on the homologous gene function annotation， gene expression level and bioinformatics analysis. PCR amplification and qRT-PCR analysis showed that， both genes contained the amino acid substitutions in the coding region in K718d if compared to K718， and both showed decreased transcripts. These results provide reference for further dwarfing gene cloning and application in maize breeding.