Abstract: Aiming at the problems that there has large,diverse and complex data in the GIS system,a bias data encryption and protection method for GIS was researched,proving it is necessary and feasible to protect data bias.The data are classified according to key and bias data protection,and different data are protected in different way.Meanwhile,a universal encryption method was discussed based on traditional method.Experiment shows that,to some extent,this solution reduces the spend of encryption and decryption.

Key words: GIS system,Bias,Encryption,Protection,Flexible