Abstract: The circular error probable is extensively used to evaluate the performance of passive location system.With the aid of the single station passive location model in high-frequency, the circular error probable is obtained, which concerning the errors of azimuth, elevation and ionosphere virtual height.Since traditional circular error probable just provides the approximate formula with probability near 50%, the new error formulae is calculates by arbitrariness probability.The simulation shows that the relative error of the theoretical result is less than 1% compared with the experiment result which validates the correctness of theoretical method.