Abstract: Iodine has been long known as an indispensable element in the synthesis of thyroid hormones. Severe iodine deficiency in diet leads to iodine deficiency disorders in humans. An isotope tracer experiment was carried out to study the chemical species and content analysis of ¹²⁵I absorbed by the Bok -choy and Ipomoea Aquatica Forsk. The results showed that inorganic ¹²⁵I, organic ¹²⁵I and residual ¹²⁵I have been detected in Bok -choy and Ipomoea Aquatica Forsk. In Bok-choy, the inorganic ¹²⁵I content is the most which up to 42.48%, and except for residual ¹²⁵I the organic ¹²⁵I content is taken up to 7.91%. But in Ipomoea Aquatica Forsk, the content of ¹²⁵I ranks as residual ¹²⁵I > the inorganic ¹²⁵I > organic ¹²⁵I followed by 64.97%, 28.36% and 6.66%. The consists of inorganic ¹²⁵I is I^-，IO₃^- and I₂ in both Bok -choy and Ipomoea Aquatica Forsk，and I^- is the main chemical species. The protein-¹²⁵I was the main form of organic iodine which respectively amounts to 22.43% and 8.68% of total iodine， the content of amylose-¹²⁵I was the least which was 0.78% and 0.40% in both Bok-choy and Ipomoea Aquatica Forsk， and the content of the nucleic acid-¹²⁵I is between them. The results showed that Bok -choy and Ipomoea Aquatica Forsk can enriched Iodinein environment. so, they could be cultivated as iodine vegetable.