Atmospheric VOCs was measured at Heshan in October 2013. The variation pattern, ozone formation potential and emission sources were analyzed. Average concentration of total VOCs observed was 26.6×10-9, while alkane＞BTEX＞alkene. Concentration of alkene peaked at early morning with large variations during the daytime; variation patterns of BTEX and CO were quite similar; concentration of alkane peaked earlier than BTEX and rised rapidly in a very short time, which indicated the influence of nearby emission sources. Ozone formation potential calculation by the speciated VOCs appeared as BTEX＞alkene＞alkane. 10 key VOCs species including ethylene contributed 80.5% of total OFP;VOCs contributed most of OFP were mainly came from petrochemistry, paint solvents and gasoline vapor during observation. 