The particle image velocimetry (PIV) measurement and shadowgraph velocimetry of the supersonic jet was conducted to investigate the convective velocity of the large scale structure in the shear layer. The Mach number was 2.0, the Reynolds number based on the diameter of the nozzle exit was 1.0×106. The single pixel ensemble correlation method (Westerweel et al., 2003) was applied to the PIV and shadowgraph images to obtain averaged velocity field with fine spatial resolution. The axial velocity calculated from shadowgraph image is about 0.7 times that of PIV. The velocity calculated from shadowgraph image is in good agreement with the estimated velocity which is calculated from screech frequency and the shock cell length by the Powell’s model.