Dendrochronology is the study of growth rings properties, and use the rings to dating and analyze the past the science of environmental change, but the discipline connotation is not limited to determine years to a fine living trees or log or wood, still can use rings inherent information recover or reconstruct the natural environment evolution of the historical process, using the rings s for the identification of ancient buildings, ancient cultural relics, ancient art. The contents of this article are composed of four subjects.(1) A survey on dendrochronology including its definition, its research objects and its brief developing process are pointed. (2) The principles and research methods of dendrochronology are briefly described, among those, crossdating, matching of tree-ring, connection of tree-ring or bridge of tree-ring are the key technology to precise date of tree-ring. It is an important means to verify the true age and the establishment the chronology of trees history. Secondly, the ecological amplitude (sensitivity principles) are the vital principle and method for selecting desirable samples site and sample tree for researchers purpose. (3) Along with the extensive and deep development of this discipline, The applied fields has been differentiated into more secondary disciplines as follows: Tree ring chronology, dendrobiology, dendroclimatology, Tree ring fire science, dendro-geomorphology, dendrochemistry, and dendroarcheology. Among those, a lot of achievements were obtained in dendroclimatology, taking Europe for instance, the chronology of trees history was obtained for thousands of years, from which dendrochronology is originated, and by which the history of ancient climate can be rebuilt in many areas. (4) Nowadays, the development of dendrochronology has entered a new stage, of which it is characterized by cytology level of perfect information. No longer limited to ring width as the main object of study. Moreover, the observation of naked eye will be gradually replaced by the image recognition technology.