Anti-inflammatory refers to the property of a substance or drug that reduces inflammation. anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the system. plethysmometer is mainly used for measuring the swelling (edema), inflammation of rat paw. it is simple instrument containing mercury, but accuracy is not achieved in this instrument and the other disadvantage is heavy metal toxicity on frequent exposures. and ugo basile plethysmometer is also used to accurately measure rat paw swelling, inflammation but this instrument is having high cost. so, here we modified the ugo basile plethysmometer. it is having low cost as compared to ugo basile plethysmometer and accuracy is also achieved compare to simple non digital plethysmometer. principle of this instrument is displacement of solution, and directly measure volume of displaced solution.