The determination of number of acts under the Administrative Penalty Act has been a controversial issue. Recently there are two material cases in practice: One is Uber’s irregularity case, resulting in a series of judicial judgments, law amendments to raise penalty to solve the single act problem, as well as extension of license suspension and revocation periods that caused disputes over adverse actions of punitive and regulatory natures, and the other case is the Chunghwa Telecom’s violation of labor law due to Project 499. The telecom company and its affiliated stores nationwide were imposed with the heaviest penalty, which involved issues of double jeopardy and joint violation of laws. This article divides the development of the Administrative Penalty Act’s practice into the following four sections: First, the determination of double jeopardy (besides Article 24 of the foregoing Act, the overlapping jurisdictions issue under Article 30 and 31 will be briefly mentioned); Second, the discussion of the constituent elements of Article 14; Third, the controversy over the Act’s jurisdiction determination; Fourth, the distinction between adverse actions of punitive and regulatory natures. The aforementioned four sections will apply to the Uber case by means of analyzing the concept, opinions in practice and judicial decisions, and to the Chunghwa Telecom case by process of administrative appeal.