Objective To investigate the differences in biological features between male and female patients with obstructive sleep apnea-hypopnea syndrome( OSAHS) . Methods 192 cases of patients with snoring were analyzed in the Sleep Medicine Center of West ChinaHospital fromSeptember 2004 to February 2005. The standard sleep disorder questionnaires, neck circumference, hight, weight, and all night polysomnography ( PSG) were evaluated. The clinical features of the male and female patients with OSAHS were compared. Results 170 cases of patients met the criteria of OSAHS for the apnea-hypopnea index ( AHI) more than 5 times per hour. Male gender accounted for 90% of the total patients ( male vs. female 153 vs. 17, 9∶1) . The age of male patients with OSAHS was younger than that of female ( 45. 7 ±11. 4 yearsvs. 58. 0 ±6. 1 years, P = 0. 000) . Parameters including neck circumference ( 37. 6 ±3. 2 cm vs. 35. 6 ±3. 2 cm, P =0. 000) , waist/hip rate ( 0. 94 ±0. 04 vs. 0. 9 ±0. 06, P = 0. 000) , AHI ( 36. 4 ±25. 7 vs.21. 4 ±17. 4, P =0. 004) , oxygen desaturation index ( 34. 5 ±27. 4 vs. 22. 2 ±20. 8, P =0. 035) , the number of smoking ( 52. 9% vs. 5. 9% , P = 0. 000) and drinking ( 46. 4% vs. 5. 9% , P = 0. 001) were different among the male and female patients with OSAHS. On the other hand, the morning headache ( 70. 6% vs.26. 1%, P = 0. 005) , mouth dry( 76. 5% vs. 47. 7% , P = 0. 025) , bad temper ( 52. 9% vs. 19. 0% , P =0. 004) , and hypertension ( 52. 9% vs. 20. 9% , P =0. 007) were more common in the female patients with OSAHS. Conclusion There are significant differences between male and female patients with OSAHS in prevalence, age, symptoms, and severity of the disease.