Ent-kaurene Synthase (KS) and ent-kaurenoic acid oxidase gene (KOA) are critical genes in the pathway of gibberellins biosynthesis. In this research, KS and KOA gene in apple, designated as MdKS (GenBank accession number: KC437681）and MdKOA1 (GenBank accession number: KC437682), were isolated from the apical tissue of ‘spur-type Fuji’ apple by touchdown PCR. The length of MdKS ORF is 2211bp, MdKOA1 ORF is 1509bp. Amino acid sequence analysis revealed that the KS sequence had 45.2%-98.8% similarity with those of other report plant; and the KOA sequence had 42.8-99.4% similarity with other plant. Subcelluar localization assays that the MdKS protein was located in the nucleus and the plasma; and the MdKOA1 protein located in the plasma. Fluorescent quantitative PCR analysis showed that the trend of expression of MdKS and MdKOA1 gene are the same in SH40 and SH28 grafted cultivar ‘spur-type Fuji’. The expression of MdKS and MdKOA1 gene in the apical tissue, young fruit and branch bark of semi-dwarf type SH28 grafted cultivar ‘spur-type Fuji’ are higher than dwarf type SH40 grafted cultivar .