In this book, Chinese astronomer He Xiangtao introduces the amazing features of quasars, the discoveries of the quasars and the methods to research quasars to the reader, which includes how the quasars were discovered, how to nd and observe them, and the popular model of the quasar structure. The book contains many modern astronomy branches and well-known concepts including redshift, spectrum analysis, superluminal jet and black hole.The book also contains essays about the memoirs of the author.