Law enforcement in China consists of an extensive public security system and a variety of enforcement procedures used to maintain order in the country. Along with the courts and procuratorates, the country's judicial and public security agencies include the Ministry of Public Security and the Ministry of State Security, with their descending hierarchy of departments, bureaus, subbureaus, and stations
Hong Kong and Macau have separate law enforcement agencies and work together with mainland agencies to deal with crime between them.
The national security system is made up of the Ministry of State Security and the Ministry of Public Security, the People's Armed Police, the People's Liberation Army (PLA), and the state judicial, procuratorial, and penal systems. The Ministry of Public Security oversees all domestic police activity in China .The ministry is responsible for police operations and prisons and has dedicated departments for internal political, economic, and communications security. Its lowest organizational units are public security stations, which maintain close day-to-day contact with the public. The People's Armed Police Force, with its 1.5 million personnel, is organized into 45 divisions. These include security police, border defense personnel, guards for government buildings and embassies, and police communications specialists.
The Ministry of State Security was established in 1983 to ensure "the security of the state through effective measures against enemy agents, spies, and counterrevolutionary activities designed to sabotage or overthrow China's socialist system." The ministry is guided by a series of laws enacted in 1993, 1994, and 1997 that replaced the "counterrevolutionary" crime statutes. The ministry's operations include intelligence collection, both domestic and foreign. Authorities have used arrests on charges of revealing state secrets, subversion, and common crimes to suppress political dissent and social advocacy.