Understanding fully the sources of historical data "Zhongyizhuan"in SONGSHI is an important prerequisite for valuing it and analyzing the shifts in idea of loyalism."Zhongyizhuan " in SONGSHI collects a number of figures with various types who lived in different periods,so the writer had to deal with multisource data.Its sources fall into three types:firstly,concerning the figures who lived in Northern Song and early Southern Song Dynasty,the sources of their biographies are mostly from such official history books as GUOSHI and SHILU;secondly,as regards those for whom there are no biographies in the official history books above,especially those loyal warriors who served in the Song-andYuan war,the sources of their biographies came from corpus,notes and local chronicles of Song,and from some of unofficial writings at the end of Song Dynasty,such as WENCHENGXIANG DUFU ZHONGYIZHUAN;thirdly,the sources of some biographies are from the epigraph,inscriptions and local chronicles of Yuan Dynasty.