Abstract: In the complex conversion analysis for multi-degrees of freedom, there are large calculation counts in every calculation step of Genetic Algorithm which limit the running speed of genetic algorithm.So to reduce the positive calculation counts is an effective method to enlarge the range of GA's application.Empirical Genetic-simplex Algorithm is one of the effective methods to solve the problem.In this paper, Empirical Genetic-Simplex Algorithm is applied to structural physical parameters identification based on the dynamic response conditions and incomplete modal parameters.The result shown that Empirical Genetic-Simplex Algorithm has advantages of precision, efficiency in searching, of being strong to resist the noise, and it is good adapting to the incomplete information.