In the present study, flow characteristics of turbulent oscillatory flow in an oscillator connected to square-sectional $180^{circ}$ curved duct are investigated experimentally. In order to investigate wall shear stress and pressure distributions, the experimental studies for air flows we conducted in a square-sectional $180^{circ}$ curved duct by using the LDV system with the data acquisitions and the processing system. The wall shear stress at bend angle of the $150^{circ}$ and pressure distribution of the inlet (${phi}=0^{circ}$) to the outlet (${phi}=180^{circ}$) by $10^{circ}$ intervals of the duct are measured. The results obtained from the experiment are summarized as follows : wall shear stress values in the inner wall we larger than those in an outer wall, except for the phase angle (${omega}t/{pi}/6$) of 3, because of the intensity of secondary flow. The pressure distributions are the largest in accelerating and decelerating regions at the bend angle(${phi}$) of $90^{circ}$ and pressure difference of inner and outer walls is the largest before and after the ${phi}=90^{circ}$.