The aim of the paper is to analyze the rationale of production of C-trees used in innovative design workshop implementing C/K theory. Data had been produced within industrial creative workshops in four Medium industries. Workshops had been conducted by the researchers and 5 C-tree had been produced and analyzed. Existing patterns and rationale in the construction of the C-trees are researched. The Analysis of the content and structure of the C-trees shows that five types of partition are used. The sequence of partition doesn't show any pattern. The subjectivity of the representation is illustrated. Mechanisms of systematic expansion of C space are also illustrated through the C-tree analysis. Based on case study, the paper discuss practical use of C-tree as intermediary object.