This article studies stupa architecture prevailing in the first and second centuries B.C. in India by examining the stone carvings of the Bharhut Stupa and related Buddhists documents. It focuses on the carved images related to architecture as well as the thought relating to stupa worship in early Mahāyāna. First, the definitions of stupa, reasons for building stupas, and forms of stupas are examined through a textual study. Second, the carvings of Bharhut Stupa with content relating to religious architecture are examined. The article explores not only Perfection of Wisdom sutras in the early Mahāyāna period, but also thought relating to stupa-worship. Furthermore, through the study of the carvings and a comparison with descriptions in texts, three types of stupa architecture may be found—disclosed stupa, house stupa, and no-walled stupa, which prevailed before 150 B.C. in India. These developments in religious architectural forms represent the progressive development of the idea of worship from sacralization to worship, to merit.