The modeling approach to the protection functions based on IEC 61850 standards is analyzed. Two models are given as examples of 3-phase over-current protection and longitudinal differential protection. The implementation methods for the modeling of the protection settings， soft strap and fault value， etc. in engineering application are proposed. It is concluded that a special institute should be established to standardize the extension of the information model so as to fully guarantee the interoperability of IEC 61850 standards.