It is becoming possible to do detailed numerical analyses for the various mechanical behavior of braced excavation by researching and developing the numerical analysis technique such as the finite element method (FEM). However, the mechanical behavior of braced excavation has not been clarified fully both in theory and in experience. Therefore, improving the prediction accuracy during the prior design is very important for making the observational method of braced excavation more effective. In this paper, FEM analyses were performed for a model of braced excavation by using Geotechnical Finite Element Elasto-plastic Analysis Software, GeoFEAS (2D). As the constitutive law of ground, MC-DP model, and Duncan-Chang model were applied. The results were compared and discussed with that of a site measurement, and the effects of the constitutive law of ground on the analyzed result were verified. For the difference between the results, the reason was investigated by the analyses adjusting the elastic modulus of ground, and the appropriate application of the constitutive law was researched. It is becoming possible to do detailed numerical analyzes for the various mechanical behavior of braced excavation by researching and developing the numerical analysis technique such as the finite element method (FEM). However, the mechanical behavior of braced excavation has not been clarified fully both in Theory and in experience. Therefore, improving the prediction accuracy during the prior design is very important for making the observational method of braced excavation more effective. In this paper, FEM analyzes were performed for a model of braced excavation by using Geotechnical Finite Element Elasto- plastic analysis Software, GeoFEAS (2D). As the constitutive law of ground, MC-DP model, and Duncan-Chang model were applied. The results were compared and discussed with that of a site measurement, and the effects of the constitutive law of For the difference between the results, the reason was investigated by the analyzes are the elastic modulus of ground, and the appropriate application of the constitutive law was researched.