It is our great honour to welcome you to the Sixth Xinglong Observational Astrophysics Workshop, supported by the Bureau of Personnel Chinese Academy of Sciences, hosted jointly by the Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences (NAOC), and the Xinglong Observatory, NAOC. The general topic for this workshop is Time Domain Astronomy. On the first day (August 1), lectures will be given at NAOC campus (Beijing). During August 2-7, participates will stay at Xinglong Observatory (Hebei Province) for the training of observations and data reductions. We look forward to the engaging discussions and exchanges of ideas.