In order to cancel the impact of gyro bias and gyro drift, discusses two-position method to achieve high north seeking accuracy. Based on two-position north seeking, an error analyzing method is given. The error models are established, which includes gyro drift, scale-factor error, level error of platform, position transformation error and introduce parameter error. Then, analyze the error features. The analysis result shows that the north seeking error is proportioned to azimuth trigonometric function or is a constant under such error sources. The result can give reference to compensate north seeking error and improve north seeking accuracy.