Abstract: Faced with Japans longterm deflation and weak economic growth, the Bank of Japan initiated QQE: the Bank of Japan continued to increase base currency, adopted negative interes tratepolicy, implemented yield curve control, and guided public expectations. Since the implementation of the policy, the time limit of inflation target has been delayed repeatedly. Although the policy improves the economic situation in the short term, it is also interfered by the global market and other countriespolicies. The poor transmission mechanism of monetary policy, the lack of stable expectations, aging population with fewer children, and the mutual restriction of fiscal and monetary policies all affect the economic effect of monetary policy.

Key words: QQE, negative interest rate policy, yield curve control