The concentration of air PM10 in six types of green lands in campus of Tsinghua university was measured. The results showed that PM10 concentration exhibited obvious daily and monthly variation,and also had remarkable difference among different seasons. However there was no remarkable difference in concentration of PM10 within the same season over all types of green lands. As for average concentration,the value was lower in arbor land of spring,autumn and winter,and in lawn of summer. The concentration of PM10 was 43% higher in cloudy days than that of sunny ones. Moreover,the difference increased to 137% between cloudy day after raining and sunny day after raining because of the clarification of rain.
