The determination of P and S waves arrival times is important for a variety of seismological applications including earthquake location and seismic tomography‎. ‎Quickly detecting and accurately picking the first P wave arrivals are of great importance in event location‎, ‎event identification‎, ‎and source mechanism analysis‎, ‎especially in the era of large volumes of digital and real-time seismic data‎. ‎Manual analysis of seismograms and phase picking is time-consuming and subjective‎. ‎Various techniques have been presented in the literatures for detecting and picking the arrivals of different seismic phases from single-component as well as three-component recordings‎. ‎In this study the wavelet transform has been used to detect and pick the arrival of compressional phases since it is suitable for analysis of non-stationary signals in multi-scale format‎. ‎In order to detect the P-wave arrival‎, ‎the wavelet coefficients are calculated using the vertical component of the seismogram‎. ‎In this study‎ the P arrival time was determined ‎by using the envelope of the wavelet coefficients and edge detection methods.