Abstract: Numbers of real-time data (E-BAM) of PM2.5 were collected in the period from Jan 8th 2012 to Jan 1st 2013 at the laboratory of Tropical Ocean University (Sanya, China). The average mass concentration was 19.7 μg/m³. The highest 40.5 μg/m³ in October compared to the lowest 14.1 μg/m³ in July. From a seasonal perspective, the average PM2.5 mass concentration in fall and winter are relatively higher than that in both spring and summer. On the basis of satellite map of fire points and backward trajectories of the air masses, we primarily deduced that the PM2.5 in Sanya may be caused by the biomass burning and industrial pollutants from the area of Pearl River Delta of China and the Indo-China peninsula (e.g. Vietnam, Laos).