Abstract: In the southeastern monsoon region of China, climatic studies based on tree-ring width have made great progress during the past decade. In terms of some tree-ring width chronologies without obvious growth limiting factors to meet the requirement for climatic reconstructions, reliable climatic signals have been successfully extracted by splitting tree-ring width into earlywood and latewood width and building corresponding width chronologies. However, how the corresponding earlywood and latewood of tree-ring width with clear limiting climatic factor respond to climate has not been investigated until now. The tree-ring width chronology of high-altitude Pinus taiwanensis was highly sensitive to prior April-July temperature in Sanqingshan, Jiangxi Province of China. In order to investigate the reason of the high sensitivity and the potential of its corresponding earlywood and latewood chronologies for climatic reconstructions, it was split into sub-annual chronologies, that is, the earlywood- and latewood-width chronologies. Both the sub-annual chronologies were found to have the same dominating climatic factor, i.e., prior April-July temperature, as the original chronology. The relationship stood for both high and low frequencies, which clearly explained why the high-latitude tree-ring width chronology was highly sensitive to climate. The study also demonstrated that the reconstruction quality using tree-ring width chronology could be influenced to some extent by whether the corresponding earlywood- and latewood-width chronologies contained similar climatic signals.