In this paper through to analyse the sensitivity of several modal parameters about the elastic modulus damage such as characteristic frequency, modal displacement, flexibility matrix and modal curvature , Combined with Fisher information matrix , got the sensitivity of modal parameters on different damage positions of bridge. Computational simulation of Jian Tiao bridge is implemented with this method to find Optimum sensor placement schemes of different parameters. And through the result of numerical analysis we know, flexibility matrix is the most sensitive parameter about damage of elastic modulus, modal sensitivity less than flexibility matrix, the third is frequency. Sensitivity of modal curvature is the dullest, its sensitivity only 1/300 than flexibility matrix. It have different sensor arrange schemes when use four different modal parameters, among them the sensitivity of flexibility matrix is highest.