[Objective] Hyperspectral estimation of canopy chlorophyll content was expected to provide a clue for obtaining growth information rapidly, diagnosing growth situation and precision management of crops. [Methods] Based on the measurement of canopy spectral characteristics and chlorophyll content of summer corn in heading stage in Guanzhong area of Shaanxi Province, a model with regard to the canopy chlorophyll content estimation was established by relating the original spectrum and the first derivative spectral reflectance of sensitive band. [Results] For the reflection spectral of corn in the heading stage, the spectral curve showed downward trend with the increase of chlorophyll content in the visible and infrared band; influence of chlorophyll content on spectral curve in the red edge band was not obvious, and the spectral curve showed upward trend with the increase of chlorophyll content in the near infrared band. Fitting precision of the estimation model with the sensitive band of the first derivative spectral reflectance were superior to the original spectral reflectance. The coefficients of determination R² of the model based on the first derivative spectral and the original spectral reflectance were 0.81 and 0.60, the root mean square errors(RMSE) were 2.39 and 4.41 respectively. [Conclusion] The sensitive bands of first derivative spectral reflectance was an important indexes for canopy chlorophyll content estimation of summer corn in heading stage. The models have positive significance to guide the plantation and the production for summer corn in the northwest of China.