The human error or error involved with human is still the major portion of the causes of marine casualties and attracting a great concern in ship operation. However, there are not so many researches conducted to investigate or develop methodologies for analyzing such causes of human error in maritime industry, which may be caused by the variety of factors affecting the performance of ship operation and the characteristics of human being. This paper aims to study the methodologies used in investigating human factors or errors in maritime field through the investigation of researches performed so far. The methodology for human factors can be usually classified into one of three types; descriptive studies, experimental research and evaluation research. Also there are many different kinds of applied researches for some specific subjects. Prior to the investigation of the root cause of marine accident related with human error, clear concept of the human factors and systematic taxonomy shall be established. Moreover, it is very important considerations in case of casualty inspection on human factors that the inspector on the accident shall have adequate knowledges, understandings on the concept of human factors including the way of research more than those of methodologies and techniques.