Abstract:Trophic interactions play an important role in ecological system. But within complex prey-predator interaction, it is difficult to study the scene of food webs with conventional methods. Recently, DNA-based approach tracking the food chain is developed fast, and gradually become a new model on vertebrate or invertebrate trophic chain. Prey species can be identified by molecular analysis on gut or feces. The main steps include primer design, cross-amplification test, lab test and collection of field samples as well as data analysis. This paper gives a brief introduction to development course of DNA-based approach tracking trophic links, and reviews the progress on prey species structure of predator, predator species structure of special prey, and the detectable time of prey. The limits of this technology and its development direction are also presented.