A major change occuring in the workplace is the willingness of union leaders, managers, and workers to experiment with various work schedules and to work toward the improvement in the QWL(quality of work life). In this study, the writer measures the level of QWL, embodies components of QWL, testifies the difference of QWL according to the demographical traits, and develops some scales to measure QWL in merchant ships. To achieve objectives of the paper, 11 hypotheses were established and a questionnaire was used, 894 proper data was obtained from 2, 910 Korean seamen working in merchant ships. Results of analyses are as follows : 1) The components of QWL in merchant ships are job, employee satisfaction, wage, welfare, working condition, supervise, colleague relations, initiative, and organization management. 2) Seamen of merchant ships are satisfied with job, supervise, colleague relations, and organization management. They are dissatisfied employee satisfaction, wage, welfare, and working condition. 3) According to demographical traits, the number of the factors significant difference(P<0.05) among components of QWL are 9 for type of ships, 8 ages of seamen, 7 for married or single, nationality of ships, and education level respectively, 5 for seamen career, for 4 rank on board and trading route of ships respectively, 2 for whether union or not and whether union involvement or not respectively, and 1 for department on board. 4) Results which tested hypotheses are as follows : For the components of QWL, married men are more satisfactory than an unmarried men, officers are more dissatisfactory than ratings, old men are more satisfactory than young men, men in high education level are more dissatisfactory than men in low education level, those who are much careers as a seaman are more satisfactory than those who are little careers as a seaman. There are significant differences in the components of QWL according to nationality and type of ships. There are insignificant differences in the components of QWL according to the shipboard department, whether union is or not, whether union involvement is or not, and trading route of ships.