Due to large difference in the amount of fertilizer applied by farmers，the nutrient content of straw，especially the carbon-nitrogen ratio (C/N) of straw，may affect the straw returning to the field.In order to explore the decomposition dynamics and nutrient release characteristics of different C/N oilseed rape straw，an incubation experiment was carried out.In this experiment，three different C/N of oilseed rape straw treatments were set up，including C/N 92，C/N 116 and C/N 136，and the nylon net bag method was used to submerged-culture for 120 days.The results showed that the straw with different C/N showed rapid decay (30.73%～33.59%) in the early stage (0～10 d)，slow decay (5.10%～6.42%) in the middle stage (11～30 d)，and extremely slow decay (4.50% of the total decay) in the late stage (31～120 d).Under different C/N conditions，the average release rate of straw was 28.32%，the average release rate of nitrogen was 46.28%，and the average release rate of phosphorus was 73.05%.The release rate of carbon was slower than that of nitrogen and phosphorus，and the final release rate was phosphorus > nitrogen > carbon.Nutrient release of different C/N stalks was different in the rapid decomposition stage.The nitrogen cumulative release rate of C/N 92 stalks was 7.27% and 15.16% higher than that of C/N 116 and C/N 136，respectively，while the phosphorus release rate of C/N 136 stalks was 1.91% and 13.53% higher than that of C/N 116 and C/N 92 stalks，respectively.However，the carbon content of straw with different C/N had no significant difference during the whole decomposition period.In conclusion，the nitrogen release rate of oilseed rape straw with low C/N was higher，while the phosphorus release rate of oilseed rape straw with high C/N was higher than that of straw with low C/N.