Abstract: [Objective] To understand the effect of different temperatures on the SPAD value of cotton leaves,the SPAD value of leaf was retrieved by hyperspectral data during the blossoming and boll-forming period.[Method]The statistical methods,such as the correlation analysis and linear regression,were used to analyze the relationship between SPAD value,original spectra,first-order differential spectra and hyperspectral parameters.[Result]It was shown that the SPAD and original spectral reflectivity of the leaf would decrease with the rising temperature.The SPAD value was correlated to the original spectra,first-order differential spectra and hyperspectral parameters.After the overall comparison of correlation coefficient,adjusted R2 and the optimization of mean relative error,the optimal estimation mode for the SPAD value,original spectra,first-order differential spectra and hyperspectral parameters were built,with the correlation coefficient being 0.81,0.857 and 0.833,the adjusted R2 being 0.747,0.844 and 0.824 as well as the mean relative error being 9.12;,5.78;and 7.72;.The model built through the combination of the first-order differential spectra 671 nm and 683 nm(Y=50.487 X683-131.617 X671+36.777)can achieve the highest accuracy in predicting the SPAD value,followed by the hyperspectral parameter and original spectra.[Conclusion]As shown by the experimental results,the hyperspectral sensing information can provide the theoretical basis for predicting the SPAD value for the cotton leaf during the blossoming and boll-forming period.