The potential of nitrogen mineralization was studied by applying organic fertilizer to soil and incubating at 25℃ for 28 weeks. The organic fertilizers used in this experiment were oil-cake (CF-Ⅰ, CF-Ⅱ) and amino acid fertilizer (AAF-Ⅰ, AAF- Ⅱ). Accumulated mineralized nitrogen (N) fits the frist-order kinetics during incubation. The N mineralization potential (No) for organic fertilizers treated soil was highest at AAF-Ⅱ treatment with a value of 27.71 N mg/100g, then followed by CF-Ⅱ, AAF-Ⅰ, CF-Ⅰ. The pure N mineralization potential (N0 treatment - N0 control) for CF-Ⅰ, CF-Ⅱ, AAF-Ⅰ, AAF-Ⅱ were 2.55, 5.83, 3.66, 8.57 N mg/ 100g, respectively. The amount of N mineralized from organic fertilizers applied soil ranged from 46% to 61% of the total N content in organic fertilizer. The half-life (t1/2) of organic nitrogen in soil treated with oil-cake and amino acid fertilizer was 17-21 days. Therefore, half of nitrogen contained in oil-cake and amino acid fertilizer was mineralized after 3 weeks application.