Due to high seismic risk in Iran, widespread damaged have occurred. Therefore, by construction of earthquake resistant structures, engineers have tried to mitigate damages in structures. Since the main references for structural design are loading and design codes, understanding the contents of these codes is very important. The aim of this study is seismic performance evaluation of intermediate concrete moment frames designed with 3rd edition of 2800 code with the 4th edition. 4 and 8 story structures (4 regular and 4 irregular structures) designed and modeled with 3rd edition of 2800 code are investigated. First, equivalent static procedure is applied on the models. Then, linear dynamic analysis (spectral analysis) is utilized for irregular structures. In the last step pushover analysis is carried out on the models. Linear analysis results show that story drifts of structures designed with 3rd edition cannot meet the requirements of 4th edition. They show up to 30% increase in story drifts and base shears. Also, static pushover analysis results in 4th edition show 5 to 7% increase in ductility and roof displacements.