In 2021，BOJ continued to implement the QQE monetary easing with yield curve control，and to introduce “special funds-supplying operations to facilitate financing in response to the novel coronavirus（COVID-19）”. At the same time，in the context of increasing global concern about climate change，BOJ launched a climate response financing operation，to promote the green transformation of enterprises. The monetary policies in 2021 present three characteristics. First，the policy is aggressive，but the quantitative characteristics are weakened. Second，the policy is more targeted and more effective. Third，it will provide financial support for sustainable economic development from a medium and long-term perspective. The main policy effects are：first，maintaining a low interest rate level without changing the depressed situation of CPI；second，the expansion of base money and the increase of money stock；third，the depreciation of the yen，the stock market is generally stable；fourth，bank loans showed an increasing trend，but the growth rate weakened. In order to solve the lack of effective demand，the BOJ will continue to maintain the ultra-loose monetary policy. In practice，BOJ will reduce its holdings of short-term government bonds and adjust the scale of its balance sheet. Ultra-loose monetary policy can reduce the cost of fiscal policy expansion；addressing climate change should focus on neutrality，etc..