Abstract： Objective To investigate the incidence and related risk factors of fatty liver in sea-duty personnel with large sample questionnaire and provide bases for precautions. Methods Medical examinations were taken to examine weight, height , level of fasting plasma lipid (FPL) and fatty degree of liver in 518 cases. Related factors were investigated by questionnaire and determined by multivariate logistic regression analysis. Results The morbidity of fatty liver was 13. 6% in this investigation. Alcohol drinking, body mass index (BMI) , hyperlipemia and age were the possible risk factors of fatty liver. Conclusions The morbidity of fatty liver in sea-duty personnel was higher compared with general population. Measures of controllable risk factors should be taken.