Karl Popper is one of the most famous cntemporary Western philosophers of science and society.His critical rationalism philosophy has drawn wide attraction in philosophy, natural science and social science comminities all around the world and arisen heated discussion.Conjectures and refutatuions is one of the important works of the author.The book focuses on the theme that knowledge grows through conjectures and refutation and constant elimination of errors.It covers a wide range of fields like the theory of knowledge, the theory of science, the theory of truth, the history of natural science and social science, and also includes many insights woth discussing.