Objective To modify the Golding edition of motion sickness susceptibility questionnaire (MSSQ) for seasickness susceptibility evaluation in Chinese male adults and to establish the corresponding grading criteria. Methods Totally 121 participants were selected to complete the MSSQ. The MSS indices were calculated by the following methods: the MSSQ-R1 included the common motion items of MSSQ in the questionnaire and omitted the correction factor in the formula. Based on MSSQ-R1, MSSQ-R2 and R3 formula had increased weights for vomiting and nausea score. The MSS grading criteria were set based on the percentiles of each MSS indices. All subjects underwent a voyage at sea under 3-4 grade sea condition. Seasickness was assessed by using Graybiel rating scales and the efficacy of the modified MSS indices was evaluated. Results The retest reliability was 0.85. As for criterion validity, each MSS index was positively correlated with Graybiel score (P<0.001), with MSSQ-R3 having the highest correlation coefficient. The correlation of MSSQ-R3 adult index (MSSQ-R3-Adt) was also higher than MSSQ-R3 itself (0.43 vs 0.39). The Graybiel score of highly susceptible subjects as judged by MSSQ-R3 criteria were significantly higher than those of slightly (P<0.01) and moderately susceptible (P<0.05) ones. The Graybiel score of highly and moderately susceptible subjects as judged by MSSQ-R3-Adt criteria were significantly higher than that of slightly susceptible ones (P<0.01, P<0.05). The accuracies of individual susceptibility evaluation and population based susceptibility as judged by the MSSQ-R3-Adt criteria were similar to those judged by the MSSQ. Conclusion The modified MSSQ is simple, practical and effective for seasickness susceptibility evaluation in Chinese adults.