Abstract： Objective To investigate gastroesophageal reflux (GER) and morbidity of gastroesophageal reflux disease (GERD) among the shipboard personnel.Methods Real-time esophalgus monitoring of pH was made on 63 healthy subjects of shipboard personnel,two hours before and after deployment at sea.Symptomatic scores (Sc) were analyzed in accordance with heartburn,restrosternal chest pain,acid regurgitation and food regurgitation.177 shipboard personnel and 139 shore-based personnel participated in the reflux diagnostic questionnaire (RDQ) and RDQ scores were analyzed based on the above four symptoms.RDQ score above 20 was classified as the GERD group,the score below 15 as the non GERD group,and those with a score of 16 - 19 were depleted ( including 39 shipboard personnel and 31 shore-based personnel).Subjects were chosen from patients who received gastroseopy from January 2004 to December 2007 and whose symptom score ( Sc ) was either equal or above eight.Further gastroscopy was performed to eliminate those diseases,such as esophagostenosis,peptic ulcer,esophageal neoplasm.Finally,187 shipboard personnel and 251 shore-hased personnel were chose as subjects.Results ( 1 )The accumulated So,the percentage of pH lower than four in total observing time,the number of acid reflux lasting over five minutes and the number of acid reflux with a pH level lower than four pre-deployment were obviously higher than those of two hours after deployment.(2)The questionnaire showed that incidence rate of GER among the shipboard personnel was obviously higher than that of the shore-based personnel;For those with a sea-duty service time above three years,incidence rate of GER increased significantly;(3)For the outpatients whose accumulated Sc was either equal or higher than eight,the occurrence rate of reflux esophagitis (RE) among the shipboard personnel was obviously higher than that of the shore-based personnel.For those with a sea-duty service time above one year,the incidence rate of RE increased significantly.Conclusions ( 1 ) For the shipboard personnel,occurrence rate of gastroesophageal reflux (GER) during deployment at sea was obviously higher than that of post deployment and its symptoms were also obviously severer.(2)The occurrence rate of GER for those who were often deployed at sea was significantly higher than that of the shore-based personnel.(3) The incidence rate of RE among the shipboard personnel was obviously higher than that of the shore-based personnel.