Abstract: Abstract: The Songnen Plain is located in the provinces of Heilongjiang and Jilin, and which is an important spring maize producing area in China. Excess maize straw resource causes large amounts of straw to be burned in the open air, which causes serious environmental pollution. Straw returning can not only solve the problem of environmental pollution caused by incineration of straw, but also return various nutrient elements contained in straw to the soil and increase the supply of soil nutrients. The straw returning is the development direction of maize production. It has great significance to study the characteristics of maize straw decomposition and nutrient release. The nylon bag method was used, the size of the nylon mesh bag was 34 cm×36 cm and the aperture was 80 mesh. The maize straw was crushed and cut into 5 to 10 cm segments after drying, 80 g of the maize straw were put into a nylon net bag and sealed with a nylon thread. The experiment set up two maize straw returning methods: buried and covered ground, with located observation for four years, both treatment fields were planted with maize in no-tillage manner. In the buried soil treatment, the nylon mesh bag was buried vertically in the ridge body, and the upper end of the mesh bag was level with the ground surface, which was basically the same as the depth of the mixed straw in the production field. The covered treatment was to lay the nylon mesh bag in the ditch, fixed with iron wire. The results showed that: 1) The maize straw decomposition rate and nutrient release rate in buried treatment were higher than that of covered treatment. The decomposition of straw was mainly concentrated in the first three years of returning to the soil, with the fastest decomposition rate in the first year, the total decomposition rate of buried and covered straw reached 60.63% and 45.53%, and the three-year decomposition rate was 91.70% and 81.96%. 2) The order of nutrient release in maize straw was K>P>C>N. For buried and covered treatment, in the first year of returning to the soil, the K release rate reached 96.26% and 84.04%, respectively; In the first year, the release rate of P was 61.63% and 54.30%, and the release rate of P of three-year was 92.03% and 83.29%; In the first year, the release rate of C was 57.58% and 45.32%, and the release rate of C of three-year was 90.96% and 82.06%; In the first year, the release rate of N was 52.65% and 41.33%, and the release rate of N of three-year was 91.70% and 81.96%. 3) The decomposition rate of hemicellulose in maize straws was faster than cellulose, and the lignin was the slowest. Among them, the hemicellulose decomposed rate of buried and covered straw was 73.70% and 54.72% in the first year and 88.78% and 86.30% of two-year, respectively; Cellulose was 59.29% and 45.31% in the first year and 80.42% and 70.86% of two-year, respectively; Lignin was 28.10% and 23.65% in the first year and 46.64% and 40.65% in two-year and 78.63% and 66.48% of three-year, respectively.