Malathion is a vital agent and indicator that kills targeted (harmful) organic of flora and fauna. Word „pest‟ has comprised of detrimental animals, plants and microorganisms. These are widely used all over the world in agriculture. several agricultural pesticides nowadays in the trend in which organisms toxicity and harmful alterations are noticeable. Malathion pesticides used as agricultural benefits for crop production. This type of pesticide mostly affects the histological and biochemical parameters of the organism. This study focuses on alterations of malathion observing special site tissues of freshwater fish Clarias batrachus (Linn.,1758). Malathion (50% EC) was ordered from super ford insecticides limited, Sikandrabad (BSR) and a volumetric practical performed to result out the LC50 96 hours of malathion. Value of malathion LC50 96 hours calculated 0.25 ppm. The SLC as 0.025 parts per million was fixed by using 1/10th of LC50 at 96 hours [1]. The effect of malathion SLC (1/10 of 96 hours of LC50) was investigated on the histology of the liver in treated groups of host fish. Specific changes were checked in liver histology using control and treated groups. Histological observations as hepatocytes degeneration, Necrosis in hepatocytes, vacuolar degeneration, congestion were recorded and analyses as per experimental requirement. The main objective of this article is to carry out a histological study to check the impacts of the Sublethal concentration of Malathion (EC50%) on the liver of “Clarias batrachus.”