Drag reducing agents (DRAs) technology is an important technology in pipeline transportation for natural gas. DRAs can overcome the defects of undercoat, such as short service life, ease to fall off, unable to be re-coated, and not applicable to old pipeline, complex construction, and so on. DRAs can effectively improve the flow and meanwhile ensure the safe operation of the pipeline. In this paper, the current research status of the drag reducing agent technology for natural gas as well as the drag reducing mechanism was reviewed. The reasons for the drag reduction of natural gas pipeline, evaluation of indoor film forming and stability for DRAs, and device and procedure of loop testing were discussed in detail. According to the synthesis method, DRAs were classified as Mannich bases, imidazolines, amides, phosphates and polymers. And they were discussed and illustrated respectively, on the basis of classification. And the scope of application for DRAs was given and the existing problems in research were presented from the aspects of mechanism, design of molecular structure, evaluation methodology and technology of practical application. Some suggestions were given for drag reducing mechanism, synthesis, evaluation methodology of drag reducing agents and their application in large-diameter pipeline.