"This is a historical moment," Xi said addressing the ceremony of the bank, which along with the BRICS New Development Bank (NDB) is expected to expand infrastructure financing, rivalling the World Bank and Asian Development Bank.
An Indian delegation headed by Dinesh Sharma, additional Secretary in the Ministry of Finance attended the opening ceremony.
In all 57 countries have joined as founding members while US and Japan stayed out.
Chinese Premier Li Keqiang will address the founding conference of the AIIB council later on the day.
The bank was formally established in Beijing on December 25, 2015. Chinese Finance Minister Lou Jiwei was elected as the first Chairman of the AIIB council. China's former Finance Minister, Jin Liqun was elected the first AIIB president.
With authorised capital of $100 billion and subscribed capital of $50 billion, Beijing-based AIIB will invest in sectors including energy, transportation, urban construction and logistics as well as education and healthcare.
China, India and Russia are the three largest shareholders, taking a 30.34 per cent, 8.52 per cent, 6.66 per cent stake respectively in the newly formed Bank.
Their voting shares are calculated at 26.06 per cent, 7.5 per cent and 5.92 per cent.
Based on the share holding, India is expected to get the Vice-President post.
The opening of the AIIB marked a milestone in the reform of the global economic governance system, Lou said in an interview earlier.
The AIIB will work together with multilateral development banks including the World Bank and the Asian Development Bank to facilitate Asian infrastructure construction and sustainable development, Lou said.
Asian Development Bank (ADB) President Takehiko Nakao in message has congratulated the AIIB.
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