Chingleput region, located around Madras, known as Jagir territory because it was originally granted by Myhammed Ali, the Nawab of the Arcot as a jagir to the English East India Company at Fort St. George, for the revenue thus assigned was intended as a contribution towards the expenses of the military aids extended for the protection of the Nawab. As Chingleput is located strategically very close to the East India Company's Settlement at Fort St. George, it witnessed military attacks during the Mysore Wars, particularly during the Third Mysore war on the economy of Chingleput. Like other regions, the revenues collected from Chingleput also helped the British to establish their hegemony in a part of South India. The economic effects of the war on the region of Chingleput especially, the revenue experiments and process of Commercialization of agriculture are discussed in this paper. This research paper has been prepared mostly based on the primary sources available in Tamil Nadu State Archives, Chennai.