Abstract: Objective: To analyze the effects of modified Z shape palatopharyngoplasty in the treatment of obstructive sleep apnea hypopnea syndrome(OSAHS).Methods: Seventy-one patients with OSAHS were treated with modified Z shape palatopharyngoplasty.The clinical parameters before and after treatment and effects in all patients were observed.Results: Compared with before operation,the BMI,AHI,snoring loudness score,CT90 and ESS score in patients decreased significantly after operation(P<0.01),but for LSaO₂,it significantly increased(P<0.01).Postoperative wound edema in 1 case,respiratory tract obstruction in 1 case and nasopharyngeal closure bad in 1 case were found,the incidence of which was 4.23%,and the patients alleviated in 2 to 4 days after treatment.The average following up time of all patients was(11±1.3) months.Forty-nine cases were cured,6 cases were excellent and 7 cases were effective,the total efficiency of which was 87.3%.Conclusions: The improved Z shape palatopharyngoplasty can effectively improve blood oxygen saturation,expand the velopharyngeal cavity ventilation area,keep the normal physiological state of pharynx mucosa and reduce the incidence of adverse reaction,which is worthy of clinical popularization.