Dr. Bhimrao Ramji Ambedkar（1891-1956） is of the most outstanding politician, social reformist, Buddhism revivalist, the chief architect of Indian Constitution, and leader of the Untouchable in modern India. He was born at the schedule caste family of the lowest stratification of Hindu society, and had been ruthlessly persecuted and discriminated by the Caste system and Untouchability . Through his life-time, he has been working to fight for the human rights of the untouchables, striving to emancipate the untouchables from the Hindu society. On 14th October, 1956, Dr. Bhimrao Ramji Ambedkar led a number of 400,000 untouchables to reject the Hinduism, and helped them to embrace Buddhism. This is of the unprecedented large-scale collective conversion movement ever in the history of India, but why would Dr. Ambedkar chose to give up Hinduism? Why would he choose to convert to Buddhism? What is the content and significance of his conversion to Buddhism? This is what the study would explore. Conclusions of this study: (1) The content of conversion to Buddhist movement by Dr. Ambedkar is: to achieve an ideal society of liberty, equality, and fraternity, which is justice and casteless. (2) The significance of conversion to Buddhist movement by Dr. Ambedkar is: as a way to fight against Hinduism, Caste system, and Untouchability. As a whole, the conversion of Buddhist movement by Dr. Ambedkar is one of the primary channels to release and rescue the untouchables.
