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Light produced by synchrotron radiation (SR) is much brighter than that produced by conventional laboratory X-ray sources. The photon energy of SR X-ray ranges from soft and tender X-rays to hard X-rays. Moreover, X-ray becomes element sensitive with decreasing photon energy. By using a wide energy range and high-quality light of SR, different scattering and spectroscopic methods were applied to various soft matters. We present four of our recent studies performed using specific light properties of a synchrotron facility, which are as follows: 1) in situ ultra-small angle X-ray scattering (USAXS) study to understand the deformation behavior of colloidal crystals during uniaxial stretching, 2) structure characterization of semiconducting polymer thin films along the film thickness direction by grazing-incidence wide-angle X-ray diffraction using tender X-rays, 3) X-ray absorption fine structure (XAFS) analysis of the formation mechanism of poly(3-hexylthiophene) (P3HT), 4) soft X-ray absorption and emission spectroscopic analysis of water structure in polyelectrolyte brushes.