In connection with wind sensitive issues for light roof structures, wind tunnel test is conducted for the wind-inducted vibration characteristics of composite roof steel structure system. In low turbulence uniform flow field, wind-induced displacement responses of a certain series of composite roof steel structure system are tested under two typical wind angles of attack, four typical wind declinations and nine different wind speeds. The dynamic displacement time histories, displacement statistics, displacement response spectra and displacement wind load factors are analyzed. The results show that the average displacement and root mean square displacement of the roof system increase with wind speed increases in the low turbulence uniform flow, and the influence is great of the wind angle of attack and wind declination on the wind induced response to roof. On the most unfavorable wind angles, the displacement wind load factor is from 1.1 to 1.4. Turbulence characteristics is the main factor that lead to the root-mean-square displacement response differences for different wind angles of attack and wind declinations , and it should be focused on in the design especially for the local area surrounding roof.