According to statistics, More than 80% percent of the world’s goods are transferred by merchant ship lines. As reported by the latest statistics in 2020, Some 11 billion tons of goods are transported by ship each year hence global economy is dependent on maritime transport, and its lack causing countries to face a crisis. Therefore the establishment of decent work in environments of merchant ships for seafarers has fundamental importance. Merchant ships of the world that are registered in more than 150 countries employed approximately more than 1.5 million seafarers and this industry also has 10000 seamen In Iran that in general, they considered as marine workers. The findings of this study show that the Maritime Labor Convention enacted minimum standards for living and working environments for seafarers at the international level. This convention is considered the fourth pillar of maritime international regulation that created to help in establishing a situation for decent work. In fact, the convention expresses fundamental rights and principles that seafarers faced in relation to the condition of work and living onboard. Therefore, they have rights that should observe by ship owners and the state flag has to confirm the situation of ships with the requirement of the convention. In addition, in maritime decent work, that seafarers having a job, they will be entitled to have the right of social support and social discourse. In other words, other factors in the work's environment, including freedom of assembly and of association, the prohibition of discrimination in employment, the observance of the minimum age, the prohibition of children under 16, the minimum wage proportional to the minimum subsistence, the existence of social security, unemployment insurance, rehabilitation, empowerment of women through the acquisition of appropriate job opportunities and the existence of social dialogue between the employer, the employee, and the government is also mandatory.