In order to decommission nuclear reactors and to improve the safety of BWR, falling jet behavior is important. BWR lower plenum consists of with various complicated structures and the falling jet behavior is affected by these structures. Thus we are developing the numerical simulation method to estimate the molten core falling behavior. To verify the code for the case of the BWR core melt accident, it is necessary to obtain the experimental data and validate the code by comparing the numerical results with experimental results. We reconstructed the previous test section that had the downcomer to simulate ABWR. On the other hand, the present test section dose not have the downcomer to simulate BWR. We conducted visualization experiment of falling jet behavior for the case of with structures and it was clarified that jet tip behavior was not affected by the downcomer. We also visualized falling jet behavior in some arrangements of structures and it is considered that external and internal flow affected the falling jet behavior and, symmetry of structures around injected point largely affected the jet falling behavior. We investigated internal and external flow and it was clarified that external flow was faster for the case with structures.