Abstract： Objective To evaluate the clinical utility of four questionnaires of Berlin,STOP,STOP-Bang (SBQ) and Epworth Sleepiness Scale (ESS) in the screening of patients with obstructive sleep apnea (OSA).Methods A total of 350 consecutive patients (302 males and 48 females,19-86 years old,average (42.9 ± 11.0) years old) with suspected OSA who underwent an overnight polysomnography (PSG) were recruited into this study.Four questionnaires of Berlin,STOP,SBQ and ESS were completed.Based on the severity of OSA which was determined by apnea-hypopnea index (AHI),the patients were classified into four groups of primary snoring (＜5 events/h),mild (5-＜ 15 events/h),moderate (15-＜ 30 events/h) and severe OSA (≥ 30 events/h).Sensitivity,specificity,positive predictive values,negative predictive values and the area under the receiver operating characteristics curve of four questionnaires were calculated.Results Using mild-moderate-severe (≥5 events/h),moderate-severe (≥ 15 events/h),and severe (≥ 30 events/h) OSA as cutoffs,SBQ had the highest sensitivity (94％,94％ and 95％,respectively).Berlin Questionnaire had the largest area under the receiver operating characteristics curve (0.784,0.732,and 0.771,respectively).ESS had the lowest sensitivity (43％,45％ and 48％,respectively).Conclusions Compared to the PSG,SBQ questionnaire has the highest sensitivity,but lower specificity;in contrast,Berlin questionnaire may have better accuracy.