Abstract: Investigation of DNA-protein interactions is fundamental to understand the mechanism underlying a variety of life processes. In this article, various types of biochemical methods in DNA-protein interaction study in vivo and in vitro at the level of DNA, protein, and the complex, respectively were briefly reviewed. Traditional assays including Nitrocellulose filter-binding assay, Footprinting, EMSA, and Southwestern blotting were summarized. In addition, chromatin immunopre-cipitation techniques including nChIP, xChIP, and ChIP-on-chip, which were widely used in epigenetics, were particularly introduced.