Basic considerations and some specific topics on the design and construction of X-ray optical systems in the Photon Factory are given. Curved crystal monochromators used in appropriate optical geometry can collimate synchrotron radiation into small focus with an extremely high intensity. Multiple arrangements of plane perfect crystals in asymmetric diffraction are most useful in producing X-ray beams of various angular and wavelength spreads. Fluorescent secondary X-rays excited from metal targets by the synchrotron radiation are strong in intensity and free from high directivity and specific polariation.