The variation characteristics of air pollution in Cangzhou are analyzed base on measurements from July 2009 to July 2011 in Cangzhou Normal College. Measurement data of NO(x) (NO(x) = NO + NO2), O3, SO2 and PM10 was used to analyze diurnal, monthly variation and annual variation characteristics of air pollutants in Cangzhou city. The results indicated that there were two peak values in the diurnal variation of NO, and PM10, and there was a single peak in the diurnal variation of O3. The diurnal variation of SO2 was similar to those of NO(x) and PM10, however, the variation trend was smoother than those of other pollutants. The seasonal variations of NO, NO2, NO(x) were the same as that of SO2, with the maximum values of these pollutants appearing in Winter, and the concentrations of NO, NO2, SO2 and PM10 were (30.0 +/- 18.9) microg x m(-3), (50.5 +/- 19.8) microg x m(-3), (80.5 +/- 38.7) microg x m(-3), (62.1 +/- 34.7) microg x m(-3) and (201.6 +/- 98.5) microg x m(-3), respectively. The seasonal variation of O3 was different from those of other pollutants, and the maximum concentration appeared in summer with the value of (44.9 +/- 11.4) microg x m(-3). The annual mean values of NO, NO2, NO(x), O3, SO2 and PM10 were (18.9 +/- 14.5) microg x m(-3), (37.6 +/- 13.0) microg x m(-3), (56.5 +/- 27.5) microg x m(-3), (49.9 +/- 16.3) microg x m(-3), (31.6 +/- 19.5) microg x m(-3) and (156.7 +/- 79.1) microg x m(-3), respectively. The dominant pollutants differed in different seasons. NO(x) (NO(x) = NO + NO2), SO2 and PM10 were the most important pollutants in autumn and winter, while O3 was the main pollutant in summer.