The scientific ideology of Khayyam was in the scope of ontology, and raising the unknowns, and posing fundamental questions regarding the existence of the universe and mankind. He suggested a paradox through infinity and belief in eternity, which was beyond the knowledge of his contemporaries. The logical result of such deep thoughts within a simple, tight and effective from of quatrain brought eternity for Khayyam, the poet, and the most exalted literary rank for the poetry in the Iranian land. The most sagacious scientist of the mecival centuries whose thought was the nature of the Creation and the unknowns of the existence, and whose pre-occupation was all searching for logical concepts, portrayed an image of deliberation and astonishment, and skepticism and bewilderment in the from of poems, and the product of this fanciful moments, enchanted the world and distinguished him as the best poet of all times among eight thousand Iranian poets. With his broad and extra- terrestrial mind, Khayyam talked about topics beyond the knowledge of the public, the topics which are still alive after 893 years and no other poet could even imitate him. The topics most frequently used in his quatrains are as follows: Life cycle:25 Hasty elapse of time:16 Pleasure:13 Fatalism:l0Wine: 10 Frivolity:9 Skepticism:9 ExistenceJustification:7 The firmament:7 Religious skeptism:7Mortality:7 Admitting to be yourself:7 Negligence of man:6Knowledge and awareness:5 Bitterness of life:4 Bewilderment:2Total quatrains:143Topics such as "life cycle" , "eternity" and astronomy" in the Persian Literature is new and novel to the same extent as his bewilderment between infinity and eternity ...,The theme of Khayyam’s quatrains are thought inciting, novel, deep and often unique, and although the theme of the poems can not be definitely categorized due to its association and implication of several ideas in them. and that such categorization can not be so accurate as it must be, once the theme and the main idea of the literary work and evaluation of the details of topics are recognized, recognition of the poet and study of the poem would be possible more scientifically and more reasonably.