Looking a glance at the history and benefits of classification of sciences, the present essay firstly explains the viewpoints of some eastern philosophers (al-Farabi, Sa'in ad-Din ibn Turkah, Mulla Hadi Sabzawari) as well as western philosophers (Auguste Comte, Francis Bacon, Andre Ampere), and then enumerates some distinguished characteristics of Avicenna's classification. In addition to the features such as rationality, totalizing induction, differentiation of types, universality and property, his classification enjoys special orderliness, normativity, and value-regarding, and also it can exhibit a clear approach to the philosophy of science.