Understanding the trends in PM levels is essential for formulating clean air plans. This paper analyzes PM data from various published sources for the years 2000 to 2010 in the Pearl River Delta Economic Zone (PRDEZ). The long-term variation in PM mass concentration is analyzed. Results show that PM , organic carbon (OC), elemental carbon (EC), and show a similar trend, increasing before 2005 and then decreasing slightly. The annual average PM concentration ranges from 49.1 μg·m in 2000 to 64.3 μg·m in 2010, with a peak of 84.1 μg·m in 2004. None of these 11 years meets the new National Ambient Air Quality standard (NAAQS) for PM (35 μg·m ). Overall average concentrations of OC, EC, and are 13.0, 6.5, and 11.8 μg·m , respectively. and respectively have concentrations of 1.5 μg·m and 2.9 μg·m in 2000 and 6.4 μg·m and 5.3 μg·m in 2010, with a statistically significant average annual trend of+ 0.2 μg·m ·yr and+ 0.1 μg·m ·yr . In certain geographic regions, OC and EC contribute most of the PM , while in other regions secondary water-soluble ions are more important. In general, OC and are the dominant components of PM , contributing 20.6% and 18.6%, respectively. These results provide, for the first time, a better understanding of the long-term PM characteristics and trends, on a species-by-species basis, in the PRDEZ. The results indicate that PM abatement needs to prioritize secondary species.