This study aimed to analyze what influential factors could stimulate imagination of design students in different design phases and explore how these factors correlate with each other. The influential factors were categorized into two groups: environmental factors (i.e., physical component, human aggregate, organizational measure, and social climate) and psychological factors (i.e., facilitative motivation, generative cognition, positive emotions, inspiration through actions, self-efficacy, and stress/challenge). These effects are seen in the design process, especially in phase one (problem definition and design analysis) and with a lesser effect in phase three (detailed design and communication). Our results also showed that the social climate factor had a close relationship with the factors of positive emotion, stress/challenge, and self-efficacy. The correlation among the factors of stress/challenge, physical component, and human aggregate deserved additional attention, as those factors might have crucial implications to instructional strategies.