In recent years, in order to solve the road safety problem derived from driving after drinking in Taiwan, the government is increasing the content and types of penalties for drunk-driving and conceiving to expand the penal limit to curb its occurrence. Among the will-be added penalties, collateral penalty is the most controversial one since it may result in punishing the innocent people. Is there are any legislative line of demarcation for drunk-driving penalty? Or, it only depends on legislators' judgment? How to draw the rational line of demarcation? For protecting people's right, these questions really need to be answered. In this work, the purpose and essence of administrative penalty are reviewed. Then, for identifying the scope of collateral penalty, it will define the definition of ‘collateral penalty’ and state its cause of responsibility. From the analysis of this study, collateral penalty, a conventional but legislative noun, without definite definition, is based on three kinds of social relationships between the drunk driver and the man who is punished in succession as causality, behavior relation, and space relation. However, penalty is not only for punishing, any collateral penalty must be with reasons of criticism on the society and ethics value. Therefore, the causes of various collateral penalties including passengers, family, alcohol owners…etc. will be explored. Finally, the result of this article will give normative suggestions to legislate against drunkdriving.