One of the issues that are discussed in the legal system of the countries is defining the concept of labor )as a subject of labor law( because precise explanation of its components leads to the determination of the territory of labor law. In order to achieve these components, the present study compares the labor law of various legal systems, (including Roman law and common Law) in countries such as France, South Africa, America, Egypt, Jordan, Japan, etc. Therefore  authors  are compared  the criteria presented in countries under study by Investigating the definition of worker in provisions,  judicial procedure and the doctrine then they classified these criteria in four major components. These conceptual elements include" provision of services by an individual", "performing the work personally", and "entitled to wages for work performed for employer", and "legal and economic employee’s subordination and dependency ", which can be taken into consideration in the country's judicial and quasi-judicial centers.