Unreinforced infill brick walls are frequently used as partition walls or exterior walls in traditional lower-rise buildings. However, the seismic behaviors and design formulas are not well specified in the existing Taiwan Building Code, therefore the unreinforced infill brick walls are usually ignored oftentime. For the purpose of analyses RC buildings infilled by adequate brick wall can have more accurate result, this paper based on some tests of brick wall and by using nonlinear analysis of SAP2000 to compare the seismic capacity assessment for RC building including infilled brick wall. The results confirm an appropriate method of simulation to the brick wall.