The fate of CR formulation of ¹⁴C-thiobencarb (thio.) was studied at the high rate of application in a model paddy field. Thio. could be released from the alginate formulation (TAL-17189) into water. The concentration of thio. in water increased with time, then declined. Thio. in water could be converted to more than 12 ¹⁴C-degradation products which changed with time. An unknown degradation product (M_o) was always prevailing after application. Thio. in water could be adsorbed by soil particles. Most of the adsorbed thio. retained in upper layer. Thio. in soil could be also degraded to more than 6 products. Thio. and its degradation products could conjugate with the compositions of soil to bound residues (BR). Thio. was 45.6% of the total ¹⁴C-extractable residues (ER) in upper layer soil at harvest. ¹⁴C-thio. in water and soil could be uptaken by rice plants. Thio. in plants existed in ER and BR. Most of ¹⁴C-residues in straw, roots, brown rice and husk were in bound form, more than 92% of the total ¹⁴C in them at harvest respectively. Thio. in plants could be metabolized to more than 9 metabolites which changed with time. ¹⁴C-thio. in straw, brown rice and husk accounted for 55.88, 6.06 and 11.18% of the total ¹⁴C-ER of them at harvest respectively. An unknown ¹⁴C-metabolite in brown rice was prevailing, accounted for 63.03% of the total ¹⁴C-ER.