Statutory law and case law. The United States belongs to the Anglo-American legal system, and its legal system has two basic characteristics: first, it takes statute law as the principle; Second, take case law as the main body. There are also administrative regulations and customary laws. Statutory law is a legal document formulated by the legislature, and case law is a precedent for the judgment made by the court and is legally binding. Administrative regulations are rules and regulations formulated by government agencies. Customary law is a local custom, which is quoted by the court when trying cases. In the United States, the Constitution is the supreme law of the country, and all other laws must obey the Constitution.