Dip-pen nanolithography is a new scanning probe lithography (SPL) technique based on atomic force microscopy (AFM), and now has made a great progress. The process of dippen lithography involves the adsorption of ink molecules on AFM tip, the formation of water meniscus, the transport of ink molecules, and diffusion of ink molecules on the substrate. More factors such as temperature, humidity, tip, scanning speed and so on will influence the process of dippen lithography. The paper analyzes in detail the mechanism of this technique, introduces synthetically the latest development, including electrochemical DPN, moremode DPN, multiple DPN, multiprobe array DPN and so on. Finally, the paper describes the characteristics and the application of DPN.