The effect of compositions ofPalmyra fruit fiber admixture on thermalstresses and other mechanical properties of Claywere investigated. The raw clay gotten fromSuryapet in Telangana state. First processed tovery fine particles of clay were also dried atatmosphere temperature to remove moisturepresent. A composite mixture of this driedPalmyra fruit fiber with the processed clay wasmade at various proportions of the Palmyra fruitfiber, with a little addition of water forplasticity. Samples of rectangular dimensionswere then produced from the mounting press bythe process of compaction with a very highpressure. The samples were dried and thenfinally fired in the furnace at 1000°C for a finalcuring. Properties which include thermal shockresistance, bulk density, cold crushing strengthand porosity were obtained by the appropriatestandard test methods. The microstructures ofthe fired samples were characterized withTrinocular Microscope.The results show that the amount of Palmyrafruit fiber admixture affects the propertiesvariously; porosity and thermal resistanceincreases with percentage increase in Palmyrafruit fiber, thermal and mecha