Arendt's theory of individual responsibility is an important topic in her ethical thought. Based on Arendt's distinction between the legal level and ethical level of individual responsibility, this paper analyzes the specific issues involved in the two levels, and focuses on the judgment criteria and dilemmas of individual responsibility at the ethical level, so as to analyze Arendt's inheritance and development of Kant's judgment thought. This work not only helps to understand the ethical concerns of Arendt's thought, but also helps to explore the issue of individual responsibility in modern society.