This book explores the petition(信访), a political system with Chinese characteristics. It is an important form of political participation for people at the bottom and an effective means of supervising officials at the grassroots level for the higher-level government. Through a half-year fieldwork of the Public Security Bureau, the author found that the operational logic of the petition seems to be different from the past, and it is the change of petition logic that leads to the dilemma that “the cost of petitioning is reduced but the road of rights safeguarding is narrowed,” or in other words, it''s easier to make a petition but harder to succeed for those who are truly wronged. This book based on the grassroots of China''s legal system is worth reading for those that are interested in studying police and petition as well as political sociology and organizational sociology.