This study shows that soil CEC and organic matter content are the two important factors that can affect the adsorption and desorption of Cu(II) and Pb(II) on the paddy soils. The highest adsorption and desorption of Cu(II) and Pb(II) observed for the 15-Year paddy soil can be attributed to its highest CEC among the soils tested. Long-term cultivation of rice can lead to an accumulation of organic matter in the paddy soils and result in a decrease in the percentage of the desorption of Cu(II) and Pb(II) from the paddy soils.This in turn can decrease the mobility of the adsorbed Cu(II) and Pb(II) in the paddy soils. Soil organic matter has a stronger effect on the adsorption and desorption of Cu(II) as compared to Pb(II) because the organic matter has a higher affinity for Cu(II) than for Pb(II).