Brahmagupta's work which is known as Brahmasphuta- Siddhanta is a voluminous work of 1008 verses, divided into 24 chapters. The main topics which are included in the earlier volumes of the book includes mean planetary motions, true planetary motions, problems of time, space and distance, lunar and solar eclipses, risings and settings of planets, the moon's cusps and shadows, conjunctions of planets. His originality in mathematics is visible in chapter eleven of his book. Brahmagupta was the first scholar who criticised the views, rules as well as the methods of some of the foreign astronomers and in India he was opposed to Astronomers like Aryabhata I, Srisena, VishnuchandraLata and Pradyumna. He attacked Aryabhata for dividing the Yuga into four equal parts, for upholding the earth's rotatory motion, for believing in the eclipse being caused by the shadows of the earth , sun and moon and not restricting itself with the traditional theory of Rahu and Ketu. As he opposes Aryabhata, it should be realised that the work has been written in his 30 years when he could hardly make any conceptions. While he more or less objects to the method of calculating the astronomical variations with Aryabhata's process which he condemns as inaccurate and incorrect, he at the same time establishes his own method of calculating the motion of the planets and the movement of the world around the sun he proclaimed to be more accurate. He gave the methods for finding the instantaneous method to calculate the regular motion of the planets, correct equation of parallax in the longitude and latitude, correct equations of drkkarma and better expression of valana.
Thus prominently the work Brahmagupta contributes in providing more accurate calculations and daily calculations which shall make Hindu astronomy more accurate. Also his work introduced new method of mathematical astronomy for the Arabs who were much influenced by the Indian Astronomy.