Abu’l -Barakat al-Bagdadi (1152) has a great contribution to historical problems of the philosophy of time. He criticised Aristotelian and periphatic understanding of the concept of time. He argued that time is "real" and has an ontological value. Time is process of "beingness ". The reality of time covers all kinds or varieties of "existence" or "being". He asserted that time is apriori concept. Time has no beginng or end. He denied that time is a "measurement of motion. This problem has attracted many modern philosophers as much as medieval philosophers. Especially Heidegger s approach to philosophy of time is quite simlar to Abu 'l-Barakat