Although a batch equilibrium technique showed that use of HPßCD resulted in the efficient removal of cyanophos from soil, a greater amount of cyanophos was removed by P. major L. with SiO2 ( Fig. 1). This latter finding may be derived from the interaction of plants, SiO2 and microorganisms, that could improve plant vigor and growth, which subsequently, affect the amounts of compounds uptake by plants ( Bouldin et al. 2006). Moreover, a large amount of cyanophos was removed from soil by rice bran (126.9 µg/g), this may be attributed to strong physical adsorption and binding of cyanophos to the adsorbent, rice bran ( Sera et al., 2005).