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Nitrogen mineralization is an important ecological process that determines ability of soil nitrogen supply. In order to provide theoretical basis for efficient fertilizer application in salinized soil, the effect of organic and inorganic fertilizers on the soil net nitrification, ammonification and nitrogen mineralization under different soil salinity were determined. By laboratory aerobic incubation, under four salt levels (0.46dS/m, 0.98dS/m, 1.55dS/m and 1.97dS/m), the same amount of nitrogen of 0.0895g/kg (dry weights of pure fertilizer/dry weights of purple soil) was applied to different treatments, and five fertilization treatments (the fertilization proportion of the organic fertilizer was 0, 25%, 50%, 75% and 100%, respectively) and one blank control were provided, which were designated as U1, U3O1, U1O1, U1O3, O1 and CK, respectively. Main conclusions were as follows: soil salt concentration was decreased with the increase of proportion of organic fertilizer applied;the increase of salt content had a strong inhibition on the amination of inorganic fertilizer. When the EC was less than 0.98dS/m, the application of organic fertilizer would reduce the effect of salt on amination, while when the EC was raised above 1.55dS/m, it would obviously delay the amination process of organic fertilizer, but it would not be completely suppressed. There was a threshold value for the effect of salinity on the formation rate of NO-3N. When the EC was less than 0.98dS/m, the increase rate of NO-3N was increased with the increase of salinity level, while the continuous increase of salinity would inhibit the formation rate of NO-3N. Compared with no fertilizer, fertilizer significantly increased the amount of net nitrogen mineralization in each salt soil, and the same salt level showed that the larger proportion of inorganic fertilizer was applied, the greater amount of net nitrogen mineralization was. Compared with the application of organic fertilizer under 0.46dS/m, the difference of net nitrogen mineralization between the treatments under 0.98dS/m salt level was decreased, while when the salt content was increased to 1.55dS/m and above, salt obviously delayed the mineralization process of organic fertilizer. It was recommended that the suitable fertilizer modes for different salt levels were as follows: non-saline soil (50% urea+50% organic fertilizer), mild saline soil (100% organic fertilizer), moderate and heavily saline soil (75% urea+25% organic fertilizer). 