This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer (UCRF) and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations: the first-order kinetics equation [Nt = N0 (1-e-kt)], Elovich equation (Nt = a + blnt), and parabola equation (Nt = a + bt0.5), with the best fitting by the first-order kinetics equation for different N (r = 0.9569** - 0.9999**). The release potentials (N0 values estimated by the first-order kinetics equation) of different N in the UCRF decreased in the order of total N > DON > urea-N > NH4+-N > NO3--N in water, and total N > NH4+-N > DON > urea-N > NO3--N in soil, respectively, being in accordance with cumulative amounts of N release. The constants of N release rate (k values and b values) for different N forms were in decreasing order of total N > DON > NH4+-N > NO3--N in water, whereas the k values were urea- N >DON > NH4+-N > total N > NO3--N, and the b values were total N > NH4+-N > DON > NO3--N > urea-N in soil. Compared with a common compound fertilizer, the N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg-1, and 5.17 kg kg-1, respectively. The ratios of different N to total N in the UCRF showed significant correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt = N0 (1-e-kt)] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form. This study examined the release characteristics of different N forms in an uncoated slow / controlled-release compound fertilizer (UCRF) and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations: the first-order kinetics equation [Nt = N0 (1 -e-kt)], Elovich equation (Nt = a + blnt), and parabola equation + bt0.5), with the best fitting by the first-order kinetics equation for different N (r = 0.9569 ** - 0.9999 **). The release potentials (N0 values ​​estimated by the first-order kinetics equation) of different N in the UCRF decreased in the order of total N> DON> urea-N> NH4 + -N> NO3 - N in water, and total N> NH4 + -N> DON> urea- , being in accordance with the cumulative amounts of N release. The constants of N release rate (k values ​​and b values) for different N forms were in decreasing order of total N> DON> NH4 + -N> NO3 - N in water, whereas the k values ​​were urea- N> DON> NH4 + -N> total N> NO3- N, and the b values ​​were total N> NH4 + -N N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg- 1 and 5.17 kg kg-1, respectively. The ratios of different N to total N in the UCRF showed accurate correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt = N0 (1-e -kt)] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form.