Karma is a crucial religious and philosophical concept in India. This essay points out, in Rgveda, Atharvaveda and Brāhmana, karma though denotes sacrifice, work or deed, the ideas of accumulation of karmic consequences, heaven and hell have been gradually taken shape. In Upanisad, good and bad deeds will have corresponding results that affect the subsequent lives. If people can reach the realm of Brahman, immortality can be also attained. Otherwise, people will be born repeatedly. Karma and rebirth become an organic component of brahman － ātman theory. Upanisad also voices out that karma can be transferred and the last thought at the point of death will determine the fate of next life. All these should not been overlooked by Buddhist scholars.
