Leishu is a unique form of ancient Chinese reference books that seem to have no counterpart in the western civilization. The original purpose of leishu was to provide quick reference to ancient texts. Therefore a leishu usually contains two parts, a knowledge structure and a large number of quoted texts from older books. In this paper we outline a preliminary investigation on two important leishu, yiwenleiju and taipingyulan, written around 624AD and 977AD, respectively. We processed the texts of both books by identifying the entries (quoted texts) with their sources, and built a system for full-text search and analysis. Two additional purposes of the system are to provide a way to compare the texts and explore such questions as text inherence and the change of the knowledge structures. We use "fish" as an example to illustrate our point.