Yellow Emperor's Canon of Medicine is the earliest medical literature that discussed constitution in Chinese medical history. Content on constitution in Yellow Emperor's Canon of Medicine is referring to Plain Conversation：Discussion on Blood, Qi, Body and Emotions, Plain Conversation：Discussion on Different Therapeutic Methods of Different Diseases, Spiritual Pivot：Twenty-five Types of People Divided According to Yin and Yang, Spiritual Pivot：Correspondence between Man and Nature, Spiritual Pivot：Abnormality, Normality, Obesity and Emaciation, and summarized and discussed from different perspectives. TCM constitution theory is always around the constitution theory foundation and basic framework of Yellow Emperor's Canon of Medicine. This paper analyzed and summarized the original text about constitution theory building of Yellow Emperor's Canon of Medicine, especially had a systematic analysis of constitutional thoughts in Spiritual Pivot：Twenty-five Types of People Divided According to Yin and Yang and Spiritual Pivot：Correspondence between Man and Nature.