Article 370 is sensitive because it guarantees significant autonomy for the Muslim-majority state.
The measure was accompanied by a telecoms and media blackout which began on Sunday evening.
There is a long-running insurgency on the Indian side. India and Pakistan fought several conflicts over Kashmir.
For many Kashmiris, Article 370 was the main justification for being a part of India and by revoking it, the BJP has irrevocably changed Delhi's relationship with the region, the BBC's Geeta Pandey reports from Delhi.
Meanwhile India's parliament is expected to pass a bill splitting Indian-administered Kashmir into two territories governed directly by Delhi.
Pakistan condemned India's decision to revoke the special status of its part of Kashmir as illegal, saying it would "exercise all possible options" to counter it.
"India is playing a dangerous game which will have serious consequences for regional peace and stability," said Foreign Minister Shah Mehmood Qureshi.
But an Indian government source said there was no external implication as the Line of Control, the de facto border, and boundaries of Kashmir had not been altered.