In this post-genomic era, we now have easy access to the genetic information of entire living organisms, and that information has been essential for biological research. The prosperity of genomics resulted from the progress of DNA sequence technologies, the development of computational analysis environments, and the establishment of biological resources. Plant genomics is one of the research fields that has strongly benefited from these technical advances. This chapter presents the evolution and transition of DNA sequence technologies and gives concrete examples of the proliferation in plant genomic research.