This dissertation investigates how Socrates understands his trial. It is a well-known fact that Socrates is accused of impiety and corruption of the young and is subsequently executed. Unlike an ordinary defendant who is supposed to make every effort to be acquitted, Socrates, behaving provocatively, seems even to induce the death penalty. By reading Plato's and Xenophon's works, this dissertation clarifies his thoughts on the trial that must be the basis of his conduct and explains how he achieves his aim. To deal with Socrates' view of the trial as a whole, this study examines three questions. First, does he believe in his own innocence? I argue that before and even at the trial, Socrates does not intend to prove his innocence effectively. He does not reveal his belief clearly, but at least it is clear that to be acquitted is not his primary purpose. Second, what does Socrates want to achieve at the trial? Socrates' primary purpose is to demonstrate his virtue in public. His speech that provocatively emphasizes his excellence as a benefactor of the city enables him to be convicted as a wise and noble man rather than as an impious corrupter of the young. Third, why does he refuse to escape from jail? I argue that by introducing the speech that defends the laws of the city, Socrates makes himself appear to be a supremely law-abiding citizen who is executed even when escape is possible. This study maintains that Socrates vindicates his philosophy before the ordinary people of Athens by making a strong impression of his moral excellence and utility to others. His presentation of philosophy makes it possible that being convicted and executed are compatible with appearing virtuous and being respected. Socrates promotes his posthumous reputation as a great philosopher, and thus secures the life of philosophy after his death by mitigating the popular hostility against him and philosophy as such. Socrates' understanding of his trial leads us to his idea of the nature of philosophy and the city, and of their ideal relationship. This dissertation is therefore an introduction to Socratic political philosophy.