Reinforced concrete structures used in many areas of our daily life constitute an important part of the building stock in the construction sector. There are many buildings such as reinforced concrete buildings, bridges, tunnels, mosques and dams, and the construction of new buildings in line with the need continues. Many uncertainty factors play a role in the design phase of these structures from the dimensioning as a result of the analysis performed under the required loadings to the implementation phase in the field. Many unpredictable factors such as errors in the analysis, defects in materials and workmanship affect the success rate of the project of the structure. For this purpose, Experimental Modal Analysis method, which is widely used in the literature, is used to determine the success rate of new structures, to determine the dynamic characteristics and damage conditions of existing structures and structural health monitoring. Natural frequencies, which are the dynamic variables of the structure obtained by experimental modal analysis techniques, and mode shapes and damping ratios corresponding to these frequencies are used in the examination of the current state and structural properties of the structures. However, this experimental data can be obtained by with foreign-source software by allocating large budgets. The results of the native experimental modal analysis and finite element model update software developed within the scope of doctoral thesis are compared with the results of the existing software in the literature. As the application, raw signal data of Gülburnu Bridge and scaled Type-1 Arch Dam constructed in laboratory environment were used. The experimental results of the developed software and the existing software were found to be closely related to each other.