Objective To analyze the parameters of floppy eyelid and obstructive sleep apnea-hypopnea syndrome (OSAHS) in order to discover the pathological basis of eyelid hyperlaxity.Methods Forty-four patients referred to the respiratory department of The Second Affiliated Hospital of Fujian Medical University and diagnosed with OSAHS were included in this study. Eyelid laxity and polysomnography parameters such as age, sex, body mass index (BMI), apnea and hypopnea index (AHI), percentage of REM during sleep, and time of SaO2＜90%, were recorded and analyzed.The control group consisted of 100 healthy people who underwent a routine physical checkup and did not have sleep disorder. Results In 44 patients who were found to have OSAHS, 27 patients (61%)were found to have floppy eyelid, which was higher than the control group (7%)(x2=5.007, P＜0.01).AHI in patients with floppy eyelid was (54.5±21.0)/h, which was higher than (31.1±21.9)/h in those without floppy eyelid (t=3.229, P=0.036). BMI in the floppy eyelid group was (29.7±4.8)kg/m2, which was higher than (25.3±3.5)kg/m2 in the non-floppy eyelid group (t=3.556, P=0.006). There was no difference in the percent of REM and time of SaO2＜90% in patients with or without floppy eyelid.AHI and BMI were correlated with floppy eyelid (r=0.494, 0.447, P＜0.05), but REM and SaO2＜90%were not correlated with floppy eyelid. Conclusion Floppy eyelid is common in OSAHS patients. High BMI and AHI are risk factors for floppy eyelid. The cause and development of eyelid hyperlaxity might be due to obesity and hypopnea.