Abstract: In the current study, NbC precipitates in a high aluminum high-strength steel were studied. The precipitation behavior of NbC precipitates in a high-Al high-strength steel with Nb contents of 210 ppm, 430 ppm, and 690 ppm and heat treatment temperatures of 1000 oC, 1100 oC, 1200 oC, and 1300 oC. Main inclusions in the Nb micro-alloyed high-Al high-strength steel were Al2O3, MnS and NbC. With the increase of Nb content from 210 ppm to 430 ppm and 690 ppm, the initial precipitation temperatures of NbC precipitates gradually increased to 1125 oC, 1200 oC, and 1260 oC, respectively. The amount of the precipited NbC in steel increased with the increase of niobium content and heat treatment temperature. When the heat treatment temperature was 1300 oC, NbC was dissolved in steel, leading to a decrease in the precipitation of NbC. A kinetic model of NbC precipitation in high-Al high-strength steel was established to predict effects of Nb content, heat treatment temperature, and heating time on the size of NbC precipitates.