Zhou Liyuan Lai Gu Tang Manuscripts[周栎园赖古堂稿草]in the National Museum of China collection includes eight letter manuscripts,copies of seven letters,a copy of an official document and biographies of twenty painters.After studying a large number of Zhou Lianggong's historical materials,this article conducts a detailed and systematic analysis of the content,date and histrial facts of those pieces.Eight unpublished letter manuscripts should be written by Zhou Lianggong to his relatives and friends after his impeachment in the eighth year of the Kangxi reign(1669).Copies of seven unpublished letters should be written by Zhou Lianggong to Tong Guozhen and Zhang Chaozhen during his tenure as the acting adminstrative commissioner of Anhui province in the sixth year of the Kangxi reign(1667).A copy of an unpublished official document shows that Zhou Lianggong was interrogated by authorities after his impeachment in the twelfth year of the Shunzhi reign(1655).There are very few historical materials so far referring to Zhou Lianggong's two impeachments and interrogation,as well as the period when he served as the acting commissioner of Anhui province.Those unpublished letters and official documents contain enormous documentation and historical value for the study of Zhou Lianggong's thoughts,emotions and social interactions during those periods of his life.