The length of work hours is one of the most important working conditions for labor (employee) in general speaking. Excess work hours create a great impact on labor's health in terms of physically and mentally. By regulating work hours to avoid long work hours on individual, permissible work hours is the main subject in labor law system. The purposes of this article are to comparing the enforcement and daily practice in overtime regulations between Japan and Taiwan, and to analyze the content of legal system as well as the issues in overtime control. This will (can) be the foundation of further study in overtime regulations.