Nansongshu 南宋書 "Book of the Southern Song" is an alternative history of the Southern Song period 南宋 (1127-1279) written by the Ming-period 明 (1368-1644) historian Qian Shisheng 錢士升 (1574-1652), courtesy name Yizhi 抑之, style Yuleng 御冷 or Sai'an 塞庵, from Jiashan 嘉善.
Qian was of the opinion that the official history of the Song dynasty, the Songshi 宋史, was much to long and recounts many redundant facts. In his 60-juan long book, Qian tried to eliminate these parts, especially the quotation of palace memorials and enumerations of occupations of state offices. For his didactic oversimplification, Qian Shisheng was criticized. The separate biographies of rebels and usurpers (jianchen 奸臣, panchen 叛臣), for example, were put by him right into the normal biographies. This method deprived the reader of the awareness that rulers should learn from such examples. He also threw together Daoist and Confucian philosophers.