Two soil sample treatments, which were less dramatically air-dried and immediately commenced incubation experiment (treatment 1) and more dramatically air-dried and stored for a long time (treatment 2), were used in the experiment. Effects of the two methods of soil samples on denitrification and mineralization were compared during a 7d-anaerobic-incubation. The results suggested that soil samples under treatment 2 significantly stimulated the decrease of NO3- content and the increase of N2O emission rate. Denitrification rate and mineralization rate in soil samples under treatment 2 were 47.3% and 31.0% higher than those of the soils under treatment 1, respectively. Air-drying enhanced soil organic matter mineralization and increased the availability of organic carbon, which was the main reason for the higher denitrification capacity in more dramatically air-dried soils. The enhanced extent of denitrification by the air-drying degree and the storage period in air-dried soils was determined by the promoted extent of organic matter mineralization. The more organic matter mineralized, the more NO3- denitrified. Therefore, the results deduced from the incubation experiment with air-dried soil samples may overestimate in situ denitrification capacity.