In order to clarify the effects of freeze-thaw cycling (FTC) on the nitrogen (N) bioavailability in the cultivated layer in the mollisol, incubation method was explored to detect the vertical distribution of soil available nitrogen (AN) in the profile of different freezing temperatures, soil bulk density (BD), soil moisture, and FTC frequency. The results showed that after FTCs, soil AN contents decreased with the increasing soil depths. The lower the freezing temperature was, the greater the fluctuation of AN with increasing depth was. The lower the freezing temperature was, the lower the peak value and mean value of AN in soil column were. The mean value of AN in the entire soil column (0—30 cm) at -15℃ was 9.3%~44.6% lower than that at -10℃; the increase of BD resulted in the AN value decreased and the AN/TN value increased. Compared with BD of 1.0 g/cm³, AN of BD 1.1 g/cm³ was reduced by 13.0%~18.6% in 0—30 cm soil depth, while AN/TN of BD 1.1 g/cm³ significantly increased by 0.6~4.7 times. When the soil water contents increased, the AN increased in surface layer (0—8 cm) and decreased in low soil layer (20—30 cm)under low BD treatment (1.0 g/cm³); while the AN increased in the layer of (4-8 cm) and decreased both of 0—4 cm and 20—30 cm soil depth under high BD treatment (1.1 g/cm³). AN was negatively correlated with pH, while positively correlated to the soil moisture, TDS, conductivity, and freezing temperature. Both the FTC happened or not influenced vertical distribution of AN, followed by temperature and FTC frequency (p<0.05). This study aimed to provide the theoretical basis and technical support for soil N management during FTCs in mollisol areas, e.g. improving soil fertility and reducing N loss.