In this research, the effect of architectural plan or structural diagram on building behavior against earthquake with equivalent static and dynamic method sis evaluated and the results of the equivalent static and dynamic analysis as well as certain combinations of the equivalent static analysis values have been reviewed and compared. Then various types of irregularly L-shaped structures with different irregular ratios (different projections ratios) and at different heights of the model were analyzed by equivalent static and dynamic method. The rate of torsion in irregular buildings was the benchmark. The classification of the results of both of the equivalent static and dynamic analysis and their comparison showed that in regular buildings with the number of different stories. The values of the equivalent static torsion (at the critical extension) and the maximum dynamic torsion is almost the same but it is not the case in irregularly L-shaped structures. In irregularly L-shaped structures, if the number of building floors is modeled to be less than 5, a slight difference between values of the equivalent static torsion (at the critical extension) and the maximum dynamic torsion is considered to be abandoned to the extent that it can be ignored. But as the number of floors increases to the above limit, this variation of torsion from the two equations of the equivalent static and dynamic analysis increases and as the number of floors increases this difference increases. According to the results obtained in this research it is suggested that in the case of irregularly L-shaped structures, it would be possible to restrict the use of the equivalent static analysis method. It also seems that under certain conditions the maximum torsion values obtained from the dynamic analysis can be obtained by constructing suitable combinations of the torsion values obtained by static analysis in two main orthogonal directions.