Abstract: Time-resolved particle image velocimetry (TRPIV) is employed to study the large-scale coherent motions (LSM) in the turbulent boundary layer. Since the spatial scale of LSM in the streamwise direction is related to the boundary layer thickness \delta , four high-speed cameras are arranged sequentially along the streamwise direction to obtain a view field of size about 6.7\delta \times 1.2\delta , sufficient to study LSM at the experimental Reynolds number of Re _\tau = 422. For streamwise velocity fluctuations at different wall-normal heights, the spatial wavelet transform along the streamwise direction is used to obtain the velocity fluctuations of different spatial scales and the corresponding energy proportion to the total streamwise kinetic energy. It is found that there exists a scale of maximum energy in the outer region of the turbulent boundary layer, whose length is about 1\delta . The turbulent velocity fluctuation field is decomposed into large- and small-scale components using the wavelet transform. The temporal coherent structure is extracted from the large-scale components in the time series using the threshold method, then transformed into a spatial one using the Taylor's frozen turbulence hypothesis and compared with the large-scale coherent structure captured directly in the spatial domain. The geometry of large-scale coherent structures is measured using the phase averaging method, and it is found that the streamwise scales of the ejection events obtained from the temporal and spatial domains are similar, while the scale of the sweep event extracted directly from the spatial domain is larger than that from the temporal domain. The results show that LSM with the streamwise length of 1\delta is the main contributor to turbulent kinetic energy. The large-scale coherent structure can be extracted from the temporal domain using the Taylor's frozen turbulence hypothesis and is in good agreement with the that extracted directly from the spatial domain.