The existing long-span bridges deteriorate with time due to fatigue, overloading, corrosion and environmental effects. To date, condition evaluation of the existing long-span bridges is important to carrying out the activities related to maintenance, rehabilitation and replacement of bridges. In this paper, a methodology was developed to evaluate the condition of the existing long-span bridges. The analytic hierarchy process was combined with the fuzzy synthesis. A procedure is given for condition rating of the existing long-span bridges as well. A bridge as the example is evaluated by this method and the results show that the damage of the bridge is marginal, which is same as the conclusion obtained from the traditional methods.