Abstract: The influence of two kinds of algorithm initial values on results in bearing-only passive location is described with geometry method. Via adding the difference of phase as a new measurement vector, converting the nonlinear system to linear system, a way to avoid this influence is proposed. In the linear system, Kalman filtering (KF) is used, and the initial values can be gotten from the measured values. Simulations show that this way can eliminate the initial value's influence, and the relative error of distance is less than 2%.