Abstract: With the development of advanced X-ray sources such as synchrotron radiation and free electron lasers，X-ray techniques are becoming more and more important as an analytical tool for advancing the frontiers of scientific research. This paper will first describe the interaction between X-rays and matter, then briefly review how X-ray methods work for detecting different physical properties, such as analyzing local, crystal, nanoscale, surface, interface and electron structures. The opportunities in the future, more advanced X-ray sources will bring for research will also be assessed.