We present a summary of the latest measurements of ozone (O3) and primary air pollutants at a rural/agricultural site in the fast developing Yangtze Delta region of China. The results of this study show elevated levels of primary pollutants (CO, SO2 and NOx*), which are about 1--5 times of those typically found in rural areas of North America and Europe. O3 pollution events are frequently observed. CO and SO2 levels are particularly high, resulting from the unique energy-use pattern in China. O3 shows strong positive correlation with NOx* and CO during periods of high photochemical activity. The O3-NOx* slope is comparable to the result from rural North America, but the O3-CO slope is substantially smaller for the Chinese site. With the anticipation of rapid changes of atmospheric composition in China, long-term measurements of key air pollutants will be necessary for documenting their trends and for studying their environmental impacts. ¿ 2001 American Geophysical Union