In recent year, a reduction of the damage to nonstructural components such as piping, ceiling, mechanical and electrical equipments or an improvement on the performance of nonstructural components has emerged as a key area of research. Therefore, the primary objective of this study was to evaluate and understand the seismic performance of the complex piping system such as a T-joint connection. Furthermore, it was targeted on evaluating the Finite Element (FE) Model of the T-joint connection based on moment-rotation relationship of the experimental tests. The results of FE analysis by OpenSees were in a good agreement with the experimental test result till the failure point in both models.