Automatic S-phase arrival time estimation is due to the complex characteristics of most of the S-onsets a topic of ongoing research. Manual as well as automated S-phase picking is more difficult than P-phase picking which is usually buried in the preceding P-coda. In this study by a hybrid method was implemented to estimate the S arrival time. The estimation of arrival time of the S wave is done in two steps. At the first, an initial estimation of arrival time is calculated using the Maximum Overlap Discrete Wavelet Transform (MO_DWT) technique. Regarding the fact that a short time after the arrival time of the S wave, the amplitude is maximized, in the next step, the final estimation of the arrival time of the S wave is calculated using an Autoregressive (AR) method. Our new Method is tested on a significant number of Kermanshah cluster earthquakes. Results of this new algorithm are compared with results based on ideas of Karamzadeh et al, (2012) and manual phase picking.