It analyzes the differences among designers’ ideation strategies influenced by different types of pictorial stimuli. Empirical study is made to observe designers’ idea outputs based on different types of pictorial stimuli by using extended linkography as a tool to visualize designers’ problem space evolution. It analyzes the numbers of ideas and links, as well as designers’ activeness, and categorizes designers based on their reactions to the pictorial stimuli. Designers have their own preferences for the distances of stimuli. Close stimuli active type of designers prefer to obtain explicit design knowledge from stimuli, which are close to the design topic, to actively generate ideas; far stimuli active type of designers are good at extracting elements from abstract pictorial stimuli which are proper for the design topic, to actively generate ideas. Providing suitable distance of stimuli to designers can guide them to have active design ideation process.