Abstract: Based on the automatic observation system data of Guangzhou Baiyun Airport from 2005 to 2017, and the observational data of PM_2.5 at Huadong Station from 2012 to 2017, this study analyzed the temporal variation and influencing factors of visibility in Baiyun Airport. The results showed that the visibility of Baiyun Airport tended to increase year after year, and the frequency of low visibility ＜ 1000 m trended to decrease. The diurnal and seasonal variation of visibility was significant, and the visibility was usually lowest in the early morning and was improved significantly in the afternoon. Visibility was significantly and positively correlated with wind speed, relative humidity, and temperature, whereas it was negatively correlated with PM_2.5 and relative humidity. Among all factors, PM_2.5 had dominant control on visibility. With increase of relative humidity, the visibility decreased slowly and markedly when the relative humidity was below and above 80%, respectively. When the wind speed was less than 4 m/s, the visibility increased with increase of wind speed at a greater rate at higher relative humidity conditions.