Uvulopalatopharyngoplasty (UPPP) is one possibility for the treatment of Obstructive Sleep Apnea (OSA). The aim of this study was study the analysis of polysomnography of pre-UPPP and post-UPPP. All patients were evaluated by means of a physical examination, the epworth sleepiness scale (ESS), the beck depression inventory (BDI) and the nocturnal polysomnography (PSG) before surgery, and 6~12 months after surgery. A total of 15 patients were investigated. All underwent UPPP. The patients were between 26 and 62 years old ($mean{\pm}SD$; $39.7{\pm}10.9$) with a lean body mass index (BMI) of $mean{\pm}SD$; $26.2{\pm}3.0kg/m^2$. The comparison of sleep questionnaires showed that after UPPP, the patients had a significantly lower BMI ($26.2{\pm}3.0kg/m^2$ vs $26.0{\pm}3.4kg/m^2$, p=0.241), ESS ($10.0{\pm}5.4$ vs $6.9{\pm}3.2$, p=0.022), BDI ($9.2{\pm}8.2$ vs $4.2{\pm}4.3$, p=0.343) and higher blood pressure ($127.5{\pm}12.1$ vs $123.7{\pm}12.0$, p=0.272) compared to before UPPP. The comparison of sleep parameters showed that after UPPP, patients had a significantly lower stage N1 ($108.8{\pm}53.1$ vs $82.2{\pm}48.9$, p=0.016), lower sleep latency ($4.9{\pm}4.4$ vs $2.0{\pm}1.7$, p=0.083), a lower total arousal number ($210.6{\pm}90.3$ vs $147.1{\pm}87.3$, p=0.019), lower oxygen desaturation index (ODI) ($30.2{\pm}20.9$ vs $10.2{\pm}15.1$, p=0.006), lower apnea-hypopnea index (AHI) ($31.6{\pm}22.4$ vs $10.9{\pm}15.4$, p=0.005), and a lower respiratory disturbance index (RDI) ($37.4{\pm}21.3$ vs $18.5{\pm}16.5$, p=0.008) compared to after UPPP. The comparison of sleep parameters showed that after UPPP, patients had a significantly higher stage N2 ($154.0{\pm}39.9$ vs $180.5{\pm}49.5$, p=0.017), higher REM ($58.5{\pm}29.7$ vs $72.6{\pm}34.0$, p=0.249), higher $meanSaO_2$ ($94.3{\pm}2.0$ vs $95.9{\pm}0.9$, p=0.043), and higher $meanSaO_2$ ($79.3{\pm}8.5$ vs $83.1{\pm}7.9$, p=0.116) than before UPPP. After UPPP, 6 patients were cured, 2 showed marked improvement, and 7 did not improve. After surgery, the success of the treatment was at 53%. The subjective patient satisfaction was higher than before the surgery.