The most ancient science that is still at the forefront of scientific research is psychology, because despite the inherent difference between the term psychology in the modern period with ancient period and medieval period, word psychology is used in the same sense in all three periods. This word, which is the root of term psychology, reaches Aristotle’s teachings in the book of soul. The hypothesis of present study is innovative services of Islamic civilization in the field of psychology and especially, emergence branch of psychology in Islamic civilization that has studied the behavior of politicians and various societies in moments of history as laws and general traditions that can be generalized to human behavior throughout time. The materials of this research are found in medieval literature and humanities texts produced by scholars of Islamic civilization. AL-Jahiz (869AD), the leader of Arabic prose and literatur , considers the method of fourth caliph, Ali ( 661 AD ) in dividing, recognizing and defining the behavior and psyche of individuals, people and cities as special, distinctive and unique that has analyzed and explained the behavior of city and its citizens and their properties in Egypt, Syria, Kufa, Mecca, Medina, some cities of Mesopotamia and has examined the specific behavior of politicians who have been at the helm of government power. The behavior of these people is at a moment in history that has an international impact. The present study is a brief explanation of the three scientific achievements of Islamic civilization in the Middle Ages, which is still useful in theoretical and clinical psychology; 1- Classification of human behavior within the values of ethics and providing a theoretical solution for their treatment by any scholars of Islamic civilization. 2- The initiative of the science of historical political psychology. 3-Report of Avicenna (1037 AD) initiative in clinical psychology research in the field of sleep, neurology, and various mental disorders such as depression, insanity, etc. and clinical ways of treating them. The empirical study of the soul by Avicenna has always been of interest to scholars and has been researched and tested in the Middle Ages by order of Frederick II (1250.AD).