Through linearizing nonlinear vehicle model,vehicle side slip angle estimation algorithms based on generalized Kalman filter and generalized Luenberger observer are formulated.An extended 2 degree freedom vehicle model considering tire nonlinear characteristics is firstly proposed,and the tire model parameters are obtained with nonlinear least square method.Through local linearization method,the nonlinear vehicle model is linearized at current working states and by using this linear vehicle model,generalized Kalman filter and generalized Luenberger observer for side slip angle estimation can be developed.Finally the effectiveness of both algorithms is verified through different handling maneuvers.Under extreme driving situation,the proposed methods can provide much higher estimation precision.