Blood type does not determine personality, people with the same blood type do not have the same personality traits, and the survey sample does not correspond to the blood type personality traits popularized on the Internet, and blood type is not correlated with personality. Character is the psychological characteristics of a person’s stable personality, which is expressed in the person’s attitude towards reality and behavior, the combination of different attitudes and behaviors, constituting a person’s unique character that distinguishes him or her from others. There are many factors that contribute to the formation of personality, including genetic factors, family factors, physiological factors and so on. The formation of personality cannot be separated from issues such as genes, upbringing, and social environment. There is no authoritative evidence to show a clear relationship between blood type and personality.