<div class="htmlview paragraph">For the vehicle stability control system, which improves vehicle yaw stability for limit driving condition, accurate vehicle sideslip angle detection is one of key issues to confirm the system performance. In this paper, an estimation method of vehicle sideslip angle is described. It is necessary that the vehicle sideslip angle estimation must be robust against road surface condition change, road bank, sensor error, brake force effect, driver's operation and so on. We have developed the sideslip angle estimation method for compensating the driving condition changes which disturb the sideslip estimation. The vehicle sideslip angle estimation using a combination of vehicle model observer and pseudo integral is proposed. The vehicle model observer includes tire non-linear characteristics for fitting actual tire characteristics. Moreover, road-tire friction, road bank and vehicle spinout judgments are developed for increasing the estimation accuracy. The developed sideslip estimation method is evaluated through full-scale vehicle tests. It was verified that this sideslip estimation experimentally confirms the system performance and robustness.</div>