Luciferase-based reporter assay is an important tool that employs bioluminescence to quickly and precisely investigate the gene of interest’s promoter activity by reporter gene expression at the transcriptional level. The promoter of the gene of interest is fused with the reporter gene (a gene that produces luciferase enzymes) and then transfected into the cells. Luciferase is an enzyme that catalyzes a chemical reaction to produce light. The bioluminescence activity of the luciferase gene in the transfected cells is directly proportional to the expression of the gene of interest, which is measured by using a luminometer. In this chapter, we outline the use of a dual-reporter luciferase assay to measure Aurora A kinase activity during the mitotic cycle.