"Typing by blood", which was proposed by popular psychologists, has been very prevalent since the beginning of the 1970s. In Japan, there is little information concerning the studies of "blood type and personality" in foreign countries. In foreign countries, the studies of relationship between blood type and disease began in the 1920s. These studies caught the attention of some psychologists in the 1960s. It is thought that there is no relationship between "typing by blood" in Japan and "blood type and personality" in foreign countries. The present study deals with the history of the studies of "blood type and personality" in foreign countries and discusses relationship between "typing by blood" and "blood type and personality".