DNA transfection techniques are necessary to perform the high throughput screening (HTS) for drug discovery. Among many transfection techniques, we will recommend the adenovirus vector for HTS as a particularly useful method. The adenovirus vector has attracted a great deal of attention as a vector for gene therapy and is also useful for studying gene functions in differentiated cells such as neurons and muscle cells. An efficient method of constructing recombinant adenoviruses has been established. In this article, we will introduce the method to produce the desired recombinant adenoviruses and show our findings using these adenoviruses.