Abstract: Popper is one of the most famous philosophers of science in contemporary Western world，whose philosophy achievements cover almost all the fields of human knowledge.With “trial and error” as the basic method，his falsificationism principle focuses on demarcation problem and induction problem.He opposes inductionism，and denies verifiability but he believes the severity of test，confirmation and fidelity are dominant characters of the falsifiability of scientific theories.He regards science as an endless，ongoing process.His model of scientific development，namely，“the problem guessrefutethe problem,” realize a quantum leap on theory of human knowledge.Popper′s falsification ideology reflects the creative spirit of science，and strict falsification: the critical spirit of science which is of important contemporary value and practical significance.

Key words: Popper, falsification principle, induction, trial and error, fidelity 