Objective To assess the clinical effectiveness and safety of uvulopalatopharyngoplasty （UPPP） in the treatment of snoring and obstructive sleep aponea syndrome （OSAS ）. Methods MEDLINE （1966 -2005 ）, EMBASE （1984 - 2005 ）, The Cochrane Library （Issue 1, 2005 ）, CBM （1979 - 2005 ）, CNKI （1994 - 2005 ）, VIP （ 1989 - 2005 ）, CMCC （1994-2005） ,Wanfang Database and Internet were searched in English and Chinese versions. Randomized controlled trials（ RC,Ts）, quasi-randomized controlled trials and prospective cohort studies were included. Study quality was evaluated by two researchers independently. RevMan4.2.7 was used for meta-analysis.Results Twelve studies were included, of which 5 were RCTs, 7 were prospective cohort studies. Compared with dental appliance（DA）, PSG （polysomnography） changes of DA group were larger than UPPP group, but patients of UPPP group had better quality of life and compliance. Comparing UPPP with LAUP （laser-assisted uvulopalatpharyngoplasty ） and RFTVR （radiofrequency tissue volume reduction）, the postoperative pain of the latter two was less than UPPP. About complications, UPPP and LAUP had no difference except for nasal reflux at 1 week after operation, there was no statistical difference between UPPP and RFTVR. There was no study to compare the PSG change among the three groups. Comparing UPPP with CPAP （continuous positive airway pressure）, PSG changes were larger in CPAP. Conclusions At present, there is no evidence to assure that UPPP is better than other treatments for snoring and OSAS or to suggest which type of surgery is most effective.The literature search is restricted to the publications of English and Chinese language, which may have resulted in missing some studies; the evidence is still weak due to the poor quality and a small number of included studies. There is an urgent need for high quality RCTs to be carried out.