Objective To analyze and evaluate the fatigue status of the ship crew , as well as the air quality of the ship cab-ins, and to find out influencing factors for the fatigue among the ship crew , so as to provide theoretical evidence and guidance for the maintenance and improvement of the health of the ship crew during prolonged deployment at sea .Methods Investigation and analysis on the fatigue status among the ship crew both before and after deployment were made by using the questionnaire of 《the Subjective Fa-tigue Symptom Checklist》.Air quality of the ship cabins was analyzed by using Gasmet DX 4035 FT-IR multi-component air analyzer and assessed in accordance with Indoor Air Quality Standards .Results (1) One week after deployment , fatigue symptoms in all the shipboard personnel deteriorated significantly , and three fatigue factors including "somatic", "mental"and "neurosensory"factors were all considerably increased .(2) The levels of formaldehyde and SO 2 in some cabins exceeded the permissible limits .Conclusion The fatigue status among the ship crew after deployment at sea obviously deteriorated , as compared with that before deployment .The levels of harmful gases in some cabins exceeded the limits as specified in the standards , which could worsen the fatigue status among the ship crew.