Objective To evaluate the diagnostic value of Epworth sleepiness scale(ESS) combined with portable sleep monitor (PM) in patients with obstructive sleep apnea syndrome (OSAHS).Methods The questionnaire of ESS was used to evaluate 156 patients with snoring,and then line PM check,monitoring apnea hypoventilation index (AHI),oxygen reduction index (ODI),the lowest oxygen saturation (LSpO2),average blood oxygen saturation (MSpO2).Results One hundred and twenty-four patients were diagnosed to be OSAHS and 32 patients be simple snore by PM in 156 patients.A total of 124 cases,including mild 42 cases,moderate 47 cases,severe 35 cases.There were significant difference in ESS score,AHI,ODI,LSpO2 and MSpO2 between OSAHS in various degrees and patients with simple snore [simple snore:(5.8 ± 2.9) scores,(3.2 ± 1.3) times/h,(3.3 ± 2.6) times,0.911 ± 0.121,0.973 ± 0.132;mild OSAHS:(9.7 ± 3.5) scores,(12.8 ± 23.3) times/h,(14.2 ± 5.7) times,0.875 ± 0.083,0.902 ± 0.095 ; moderate OSAHS:(12.9 ±4.8) scores,(27.6 ± 4.5) times/h,(25.6 ± 6.1) times,0.816 ± 0.069,0.851 ± 0.071 ;severe:(16.1 ± 5.2)scores,(43.6 ± 7.6) times/h,(38.6 ± 7.8) times,0.701 ± 0.061,0.795 ± 0.063] (P ＜ 0.05).With the severity of OSAHS increased,ESS score,AHI,ODI increased gradually,LSpO2,MSpO2 gradually declined,there were statistically significant differences (P ＜ 0.05).ESS score was positively correlated with AHI and ODI (r =0.42,0.51,P ＜ 0.05),and negatively correlated with LSpO2 and MSpO2 (r =-3.70,-4.50,P ＜ 0.05).Conclusions There is a good relativity between ESS score and the monitoring index of PM.Combination of ESS with PM could be used as a primary diagnostic method in patients with OSAHS,especially in primary-care hospitals.