Qualitative analysis has increasingly become a main analysis tool for handling complex dynamical systems. In qualitative analysis, Qualitative Evaluation Problem is one of important problems. At present, qualitative analysis approaches cannot solve effectively this problem because they use unsuitable qualitative value spaces and related algebras for representing and operating qualitative values. In this paper, we develop a new type of qualitative value space called ternary qualitative space, where qualitative values are represented by ternary vectors, and build a novel ternary qualitative algebra on such a space along with a set of arithmetical operations. Using ternary qualitative space and algebra, we develop a novel approach to solve this problem. The effectiveness of our approach for this problem is demonstrated and is further illustrated by an example.