The purpose of this paper is to describe the way to represent the skills in dementia care based on the multimodal communication analysis by a computational approach. With the rapid growth of an aging population, it is becoming extremely important to elucidate communication skills for improving the quality of life of the elderly. Focusing on the dementia care method by HUMANITUDE, we have analyzed dementia care skills to evaluate their effectiveness. We designed three layers for representing skills and named them “Intra-modality”, “Inter-modality”, and “Multimodal-interaction”. These results are a part of the findings of empirical analysis of building human relationships.