Abstract: By the method of simulating laboratory experiment, we set up a batch of Albic and Black soil columns to study the effects of applied biochar derived from corn cob on the volume of leachate, soil pH, and the loss of ammonium nitrogen(NH₄⁺-N) and nitrate nitrogen(NO₃^--N). Results showed that biochar can effectively increase water-holding capacity and soil pH. Adding 2% biochar significantly decreased the N leach in the Albic soil and the Black soil by 12% and 15%, respectively. While when 4% biochar was added, the N leaching in the Albic soil and the Black soil decreased by 13% and 5%, respectively, compared with the treatments of adding 2% biochar. N fertilizer firstly adsorbed by biochar and then mixed with soil significantly decreased the N leach compared to soil mixed with fertilizer and biochar directly. The decrease N leaching effect of biochar varied among different N fertilizers. In the Albic soil, compared with the treatment of no biochar, adding 2% biochar decreased the N leaching of ammonium sulfate, potassium nitrate and urea by 8%, 15% and 12%, respectively; while in the Black soil, adding 2% biochar decreased the N leaching of ammonium sulfate, potassium nitrate and urea by 5%, 18% and 12%, respectively.