The theoretical basis and data support for the long-term response patterns of the soil-crop system carbon cycle to climate warming can be obtained by investigating the variations and influencing factors of the decomposition coefficients of winter wheat root residue and straw under warming condition. In order to investigate the effects of diurnal warming with one growing season on the decomposition coefficients of winter wheat residues (root and straw) and the soil enzyme activities and relevant physical and chemical properties, an indoor incubation experiment was performed. The winter wheat root residue and straw for the one-season diurnal warming and control treatments (coded as W-root, W-straw, CK-root, and CK-straw) were sampled in field. There were four treatments of W-root, W-straw, CK-root, and CK-straw, and each treatment included four amendment levels of 0.3, 0.6, 0.9, 1.2 g. These root residue and straw were added into the soil for incubation. Soil CO_2 emission and soil pH, dissolved organic carbon (DOC) content, and activities of urease, invertase, and catalase after incubation were measured. Results indicated that there was a significantly linear regression relationship between soil CO_2 emission and the amount of residue (root residue or straw) addition. The slope of the regression function represented the decomposition coefficient of crop residue. The decomposition coefficients for W-root and CK-root were (0.26990.0080) and (0.24070.0090) mg·g~(-1)·g~(-1), respectively (the former was significantly higher than the latter), while they were (0.25730.0030) and (0.25870.0150) mg·g~(-1)·g~(-1) for W-straw and CK-straw, respectively (no significant difference with P>0.05). Soil CO_2 emission decreased significantly (P<0.001) with the increase of soil pH but increased significantly (P<0.001) with the increase of soil DOC content. There were highly significantly (P<0.001) relationship between soil CO_2 emission and urease, invertase, and catalase activities. Urease, invertase, and catalase activities explained 75.7% (R2=0.757), 80.3% (R2=0.803), and 92.7% (R2=0.927) variations in soil CO_2 emission, respectively. Our results indicated that simulated warming significantly increased the decomposition coefficients of winter wheat root residue, but it had no effects on the decomposition coefficients of winter wheat straw. The relationship between the CO_2 emission rates from the soil with root residue and straw added and enzyme activity can be explained by the natural logarithmic models.