10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 3 2012 (July - September) The activity of fungicides is intimately related to its chemical structure. Knowledge about the chemical structure of a chemical is useful for the synthesis of new compounds with more specific actions and fewer adverse reactions, to increase/decrease the duration of action of the original fungicide or to get a more potent compound, to restrict the action to a specific system of the plant body and to reduce the adverse reactions, toxicity and other disadvantages associated. We can understand the basic chemical groups responsible for fungicidal action. A systemic fungicide is defined as systemic fungi toxic compound that controls a fungus pathogen remote from the point of application and that can be detected or identified lessThan sup greaterThan 2 lessThan /sup greaterThan .These compounds are absorbed by the plant and get translocated within it, thus providing protection as well as eradicating already established infection. Dr Jyotsnachauhan, Ashish Kumar Sharma X-ray crystallography, Systemic fungicides, Triazole structure 414-417