In Ayurvedic literature the term Oja is recognized as one of the most important, vital and radiant element of the human body but its exact nature is not understood by the Ayurvedic research community. The entire metabolic activities occurring in the human body throughout the lifetime are primarily dependant on Oja. The term Oja is occasionally ascribed to the vital body elements viz. Dosha, Dhatu, Mala according to its peculiar patterns of manifestation and in addition to this tri-phasic behaviour. Oja also manifests itself in the form of radiant energy alone in the human body.In Ayurveda Bala,Veerya,Shleshma are often considered as synonyms of Oja.Therefore in this review article attempt is made to understand the concept of Oja and ojavikruti.