Mohammad ibn Musa Khawrazmi, one of the most famous mathematicians of Iran in the 9th century, invented a new science which is called today ‘algebra’. Thanks this science he could solve all the quadratic equations of his time. In fact, he developed a theory for systematically solving quadratic equations. In this theory, he distinguished firstly the five types of algebraic equations.Secondly, he gave the algorithms to solve these equations. Thirdly, he gave the geometrical proofs for these solutions. Indeed, Khawrazmi went beyond merely providing the sort of algebraic recipes found in Babylonian texts, by insisting in further adding geometrical proofs for algebraic facts.Khawrazmi' s contribution and influence are tremendous. In 1140 Robert of Chester translated Khawrazmi's book into Latin as ‘Liber algebrae et almucabala’. When Khawrazmi's work became known in Europe through Latin translation his influence made indelible mark on the development of mathematics in the West especially in Italy. For example, Cardano, an italian mathematician, opened his ‘Ars magna’with a brief historical passage in which he first traced his intellectual lineage from Khawrazmi through Fibonacci to Pacioli and then outlined the sixteenth century developments on the solution of the cubic equation.