Abstract: The color characteristic parameters of the images of Pengan 100 Jincheng's leaves captured with multi-spectral camera MS3100 were acquired by the Adobe Photoshop software. Then the relationships between the color characteristic parameters processed by the mathematic transformation and normalization and the nitrogen contents of the Jincheng 100 leaves were analyzed, and the regression model were established. The results show that the color characteristic parameters, G-B, G/(R+B), (G-B)/(G+B), G/(R+G+B) and g-b have significant non-linear correlation with the nitrogen contents, and the monitoring models of Pengan 100 Jincheng leaf nitrogen contents based on image color parameters, G-B, (G-B)/(G+B) and G-B are better. The correlation coefficients, the determinant coefficients and the errors of prediction are same for the parameters, and 0.84, 0.70 and 3.70%, respectively. Therefore, it is feasibility to monitor nitrogen content of Jincheng leaves by using computer vision technology.