Objective To observe the motion sickness among undergraduates during their first maritime practice,and to explore the relationships between gender,traditional Chinese medicine(TCM)constitution,psychological factors,susceptibility to motion sickness and nautical motion sickness.Methods A total of 120 sophomore students were selected by simple random sampling.The Constitution Classification and Determination Scale of TCM,Beck depression inventory-short form(BDI-SF),state trait anxiety inventory(STAI)and modified motion sickness susceptibility questionnaire(mMSSQ)were used for a questionnaire survey among the students.Seasickness discomfort was assessed by Graybiel scale when they first entered the rough sea.Results A total of 104 trainees completed the questionnaire.The physical constitution was mainly characterized by damp-heat,phlegm dampness,Qi deficiency,and Yang deficiency.There was no significant difference in the incidence of motion sickness among the students with different constitutions(P<0.05).Depressi on was found in 16 people(15.38%),and depression was highly correlated with the susceptibility to motion sickness and anxiety(all P<0.01).Fifty-six students(53.85%)were highly susceptible to motion sickness.All the students felt discomfort when they first entered the rough sea,and the discomfort in females was significantly stronger than that in males(P<0.01).Motion sickness occurred in 54 students,the incidence of motion sickness in females was higher than that in males(P<0.01),and the incidence of motion sickness in the students with depression was higher than that in the students without depression(P<0.01).Gender,Yang deficiency constitution,degree of depression,and susceptibility to motion sickness were significantly correlated with the motion sickness(P<0.05),and could be used as predictors of motion sickness.Conclusion There is a high incidence of motion sickness among college students during their first maritime practice.More attention should be paid to female students,and to students with Yang deficiency constitution,negative emotions(depression and anxiety)and high susceptibility to motion sickness.