The new BRICS bank opened for business in Shanghai on Tuesday, China's official Xinhua news agency reported.
The so-called emerging BRICS countries are made up of Brazil, Russia, India, China and South Africa, and their New Development Bank has been seen as a challenge to the Washington-based International Monetary Fund and World Bank.
The opening -- announced in a short despatch -- comes two weeks after a BRICS summit hosted by Russian President Vladimir Putin.
Moscow -- which has suffered huge currency fluctuations and struggled to attract investors since the outbreak of the crisis in Ukraine -- sees the bank and a BRICS currency reserve pool as an alternative to international financial institutions like the IMF and World Bank that are dominated by the United States.
At the time of the summit Russian Foreign Minister Sergei Lavrov said in a statement that BRICS "illustrates a new polycentric system of international relations" demonstrating the increasing influence of "new centres of power".
The BRICS nations represent 40 percent of the world's population and agreed in 2013 to establish the bank, with estimated capital of $100 billion (90 billion euros).
China, the world's second-largest economy, is also leading the setting up of another new multilateral lender, the Asian Infrastructure Development Bank (AIIB), which will be headquartered in Beijing.
China will be the biggest AIIB shareholder at about 30 percent, according to the legal framework signed late last month by 50 founding member countries.
The United States and Japan -- the world's largest and third-largest economies, respectively -- have declined to join.