This paper sums up the existent methods of SPOT true color image simulation and puts forward a new

simulation method based on neural networks, which uses the powerful function of the neural networks in learning from

samples. Firstly, the model studies TM/ETM+ data. Secondly, after repeated training, the model obtains the

appropriate model parameters between the TM B (blue) band and other bands such as NIR (near infrared), R（red） and

G (green) band. Thirdly, the model is applied to SPOT images. According to the NIR (near infrared), R（red）and G

(green) bands of SPOT, the B (blue) band is simulated. The final step is the synthesis of the SPOT true color image.

Test result shows that the method is superior to the traditional methods in simulation of SPOT true color image.