Abstract: The environmental and biogeochemical migration of iodine in soil and its effect factors were studied by ¹²⁵I tracer and experiments of leach and absorption by Chinese cabbage to iodine under simulated condition. The quantitative model of iodine in soil transfer was determined. The results showed that the quantities of transfered, volatilized, leached of ¹²⁵I in soil had relations with the texture of soils, and the pH of leachate had an important influence on iodine being washed away from soil. ¹²⁵I in soil could be taken up rapidly by the Chinese cabbage roots and most of them were transported to the stem and leaf. The ¹²⁵I enrichment capacity in different parts of Chinese cabbage were ranked by root>stem>petiole>leaf. The more of ¹²⁵I was preserved by soil, the more of ¹²⁵I was absorbed by the plants. These results provide important scientific basis for preserving iodine in soil and enhancing efficiency of plants absording iodine.