Knowing exact molecular structure is essential for understanding the properties of molecules, their interaction with the environment and the reaction mechanism. Many structural methods such as X-ray crystallography, electron diffraction, solution scattering, NMR, and XAFS have been developed and greatly improved, but identifying exact molecular structure in solution is still not a trivial job. Recently, we developed pump-probe X-ray solution scattering by using the X-ray pulse, instead of optical pulse, as a probe and gives the time-resolved scattering response sensitive to global molecular structure. Pump-probe X-ray solution scattering is a tool to circumvent limitations of optical spectroscopy and other structural methods. Since X-ray scatter from all atoms in the solution sample, TRXS can track not only the reaction pathways of the solute molecules but also the solvent behavior and the solute-solvent arrangement, thus providing a global picture of the reactions. We has had much success in visualizing structural dynamics of small molecules and proteins in solution with 100 ps time resolution using pump-probe X-ray solution scattering technique based on 3rd-generation synchrotrons. For example, TRXS has found that the major reaction intermediates upon photodissociation in iodoform (CHI3) is CHI2 radical rather than CHI2-I isomer and it is contradict to the previous spectroscopic studies. We have also used TRXS to identify famous symmetry breaking phenomena occurred in the I3- ion in water solution. I3- ion has asymmetric-bent structure in water solution while it has symmetric linear structure in acetonitile solution. With the aid of X-ray free electron lasers, the time resolution of TRXS can be improved to 100 fs. With this higher resolution, real time observation of ultrafast chemical events such as bond-breaking and bond-making will be possible.