In recent years, biochar, a new environmentally functional material, has received widespread attention as a soil amendment for its special structures and characteristics, such as improving soil texture and increasing crop yield. However, controversies still exist for the effects of biochar addition to soil nitrogen(N) cycles. This study focuses on the influences of 350ºC peanut biochar application on N mineralization in abandoned orchard soil during a 46-day incubation. The treatments contained control (CK), 1% biochar (BC), and 3% biochar (BC). Results showed that 350ºC peanut biochar increased soil pH and EC, but decreased soil urease activities significantly. Biochar decreased soil net-mineralized N significantly, and a higher biochar addition content resulted in lower soil mineralized N concentration. NO₃^–-N content accounted for more than 94% of soil inorganic N for all three treatments during the entire incubation time, while the presence of biochar did not change this characteristic. Conclusions indicated that the addition of 350ºC peanut biochar significantly inhibited orchard soil N mineralization in a short time by altering soil physical and chemical properties.