Abstract: The design matrix may be a rank-defect matrix and the co-variance matrix of the observations may be the singular matrix,this generalized Gauss-Markov model is a uniformity model with simple form.Based on the principle of the Least-square estimation V^TQ^-V=min,this paper deals with the parameter estimation theory and method of the generalized G-M Model,explaines the coincidency of various adyustment rules such as V^TQ^-V=min and Rao and Bjeharmmar's.The paper discusses also the solution of the generalized G-M model and its charecters.