Strength calculation of complex structural systems is always difficult. It spends a lot of time and effort. However, with add of computers and specialized computing software such as SAP 2000, Cosmos, StruCAD, KCW 2010, RSA... the calculation of complex structures conveniently becomes. In addition, among great projects in Vietnam, most of the calculations are made by foreign companies or experts because they are contractors or have experience in similar works. This article introduces the results of durability and stability calculation of supporting structural system of Electrostatic Precipitator made by National Research Institute of Engineering Mechanical using RSA software. The calculated results are equivalent to the calculated results of the Kondor-Eco ISC based on Russia.