This paper presents the wind characteristics of an existing long span bridge based on the measured wind data. The wind data obtained from the two measuring stations on the Seohae bridge are processed and statistically analyzed. The Weibull distribution is used to model the wind speed on the bridge. The parameters of the Weibull distribution,k andc are estimated using two methods, the that the two methods give a good fit to the distribution of the measured wind speed data on the bridge. The dominant wind directions on the FCM bridge are northwest and east. The wind rose diagram shows that strong winds usually come from the northwest. From the Weibull distribution for each direction, it can be known that the parameters ofk andc are quite different according to the wind direction.