Asymmetric diurnal warming is one of the main features of global climate change, but the effects of nighttime warming on CH₄emission from paddy fields is unclear. A field experiment with rice was conducted at the Station of Agricultural Meteorology, Nanjing University of Information Science and Technology, Nanjing, China, to investigate the effects of passive nighttime warming on CH₄ emission in a paddy field and rice canopy hyperspectral characteristics. CH₄ emission flux was estimated with hyperspectral data. The tested rice was hybrid rice cv. Y Liangyou 3399. The tested paddy soil was classified as a Typic Stagnic Anthrosol. The experiment was designed with two levels of warming, i.e., nighttime warming(NW) and control(CK). NW was created by covering the rice canopy with an aluminum foil reflective film at night(19:00-6:00).CH₄ emission was measured by the closed chamber method at one-week intervals during the rice-growing period. The results showed that NW significantly increased CH₄ emission at the rice jointing and heading-grain filling stages. Compared to CK, NW increased the reflectance of the near-infrared spectrum on the canopy at the tillering and jointing stages, but decreased at the heading-grain filling and maturity stages. Positive correlations were observed in the relationships of CH₄ emission with spectral reflectance and the first derivative and the characteristic value of the spectrum. After comparing correlation coefficients (R²) of the fitting models and prediction models, the quadratic polynomial model by 'Area of Blue Edge' (SD_b) was found to be the best model(fitting model R²=0.70, prediction model R²=0.72) for estimating CH₄ emission. The results of this study provide a theoretical basis for and demonstrate the feasibility of non-destructively monitoring of CH₄ emission in paddy fields.