We often incorporate endgame heuristics as part of the evaluation function for Chinese Chess programs. In order to aggregate endgame knowledge effectively, we propose a Chinese Chess endgame knowledge-based system to construct a large set of consistent endgame heuristics, called endgame knowledge base, which is used in our program, Contemplation. The knowledge-based system consists of the acquisition module, the inference module, the inquiry module and the verification module. This system implements our graph model that has the functionality of maintaining consistency and improving its correctness. The experimental results on self-play test show that the playing strength of Contemplation has a distinct enhancement with this knowledge base.