Abstract With the rapid change of industrial structure and economical environment and the influence of globalization, the industrial patterns of employment in Taiwan also face a tremendous transform. At present, the employment of temporary workers which develop rapidly in Taiwan causes the attention and operation of relative group and enterprise, and comparing with Japan, Korea, and Singapore, these countries have official laws to stipulate dispatched work agency, user enterprise, and dispatched worker. Under the circumstances of the lack of stipulation of laws and the intermingled enterprises, the quarrel cases of labor market take place in succession. The factors cause the controversial issues of the legitimatization of the Worker Dispatch Law to come stage again. The study focuses on the necessary of the legitimatization of the Worker Dispatch Law and concludes following findings. Chapter one is introduction concluding the motivation, purpose, and procedure of the study. Chapter two is a retrospection of the development of dispatched workers, concluding the basic ideas and characters of dispatched workers, and the legitimatization of the Worker Dispatch Law and relative satisfaction references to certify the status of the study. Chapter three is an investigation of legitimatization of the Worker Dispatch Law in other countries. And chapter four is a development and tendency of dispatched workers in Taiwan. Chapter five is a research of the relationship of dispatched work agency, user enterprise, and dispatched worker, which analyzing the necessary of the legitimatization of the Worker Dispatch Law by case studies. Chapter six is a conclusion focusing on inducing the conclusions from previous chapters, positing the conclusions and suggestions.