KalaDravya is unavoidable. It is Nitya and Vibhu. It effects on all the things on the earth. While treating disease medicine should be given according Kala, Desha, Matra etc. Heena, Ati and mithya yoga of Kala acts as an etiological factor. Jara is KalakrutSwabhavabalpravruttavyadhi. Doshavasthaalso changes with kala. Garbhadharana requires particular Kala. Shodhana, aushadhisangrahan is also done in specific kala. For ingestion of medicine DashavidhaushadhiSevanKalas are described. Sadhayasadhyata of disease also changes with kala. So kala plays an important role in our life.