Abstract: In this paper, the study is conducted around a three span prestressed concrete (PRC) continuous rigid frame bridge with a main span of 190 m and consisting of two parallelly-arranged roadway boxgirders. By wind tunnel tests of an aeroelastic model, the aerodynamic coefficients of the front and rear girders are discussed and the effect of horizontal angle of airflowβon these coefficients is also studied. Then, a measurement usingthe thin plate to connecthorizontallythe two parallelly-arranged boxgirders is taken, and its vibration suppressing effect on the wind induced response is analytically discussed. It is shown that for long span rigid frame bridges with two parallelly-arranged roadway box girders, connecting horizontally the two girders in cantilever construction stage can reduce the wind induced horizontal vibration response effectively and easily.