Abstract: From the ideological spectrum, Kierkegaard's Existenzphilosophie inherited from the German Romanticism, opens the modern thought of German.In the ways of expression, Kierkegaard followed Socrates's thought “midwifery”, advocating the indirect communication.His doctrine is neither the philosophy of the thinking form, nor a religious arguments, but a poetic construction.Based on Kierkegaard's most poetic writing Either/Or, the essay analyzes its poetic cause, the basic concept of existenzphilosophie and the unity relation between “thinking” and “poetry”.