In the 1970's, the X-ray crystallographers have expected to use synchrotron radiation for further developing their researches. We have cooperated to construct the synchrotron radiation facilities, Photon Factory and SPring-8 from the user side. In this report I look back my activities in the user communities to realize the synchrotron radiation sources. Next, I describe some scientific achievements made using synchrotron radiation. They include the studies of X-ray dynamical diffraction, X-ray optics, X-ray surface diffraction, X-ray nuclear resonant scattering, and X-ray quantum optics.