Fatigue of maritime workers has been regarded as a potential cause of marine accident or a factor that contributed to human errors. However a recent related study figured out that fatigue of maritime worker sclosely affected practicing a job and is one of main causes to bring human errors. So, whether to consider human factors on maritime field or not is becoming an object of interest. In this paper, for easily measuring fatigue of maritime workers in onboard, maritime crew fatigue assessment system (McFAS) based on smartphone application was developed. McFAS was composed of flicker tester, fatigue tester and job stress tester and was verified through comparison of results with other fatigue measuring equipment.