Abstract: How to implement computer-aided product disassemblability analysis in the phase of conceptual design without complete and quantitative information is addressed. At first, the products' features at the conceptual design phase are clarified, and a new concept of qualitative assembly model that describes assembly relations among components and qualitative shapes of the components is proposed. Then, a disassemblability analysis method is presented. By analyzing components' motion feasibility and motion directions based on the qualitative positions and shape relations, disassemblability analysis can be achieved.