1 function  as banks for the government and for other banks. ZF的银行和其他银行的银行。

2   implement monetary policy - either the government's, as in Britain, or their own, if they are independent, as in Germany and the USA. 执行货币政策
    3   control the money supply控制货币供应量，

4   fix  the minimum interest rate. 限定最小利率

5   act  as lender of last resort to commercial banks with liquidity problems. 为资金流动有问题的银行充当最后贷款人。

6   issue coins and bank notes. 发行硬币和银行券

7   influence (floating) exchange rates by intervening in foreign exchange markets.通过干预外汇市场来影响浮动汇率。

8   supervise the banking system. 监管整个银行系统。

Central banks are key economic policy institutions in most modern economies. But around the world, the role and functions of central banks have been under challenge from  changing fashions in monetary policy and from the deregulation and globalization of financial markets.

The central banks usually began their existence as a banker that dealt exclusively with the national government, that really provides credit to the government of the country and in return for so doing, gets particular privileges which quite often is a monopoly on the issue of paper money.

From that strength, as these banks become large and important ,they acquire, almost by natural process, a vitally important function and that is what we've called a lender of last resort.

Support for the safety of the banking system via a lender of last resort mechanism became the most important function of central banks in the early twentieth century. However, the capacity of central banks to support commercial banks in trouble should not be overestimated.

Central banks have never actually had that much capital of their own, and they've never been able to finance any large scale rescue entirely on their own. Instead they act as information gatherers and co-ordinators of the banking system and they encourage and corral the banks as a group to provide support and assistance to the bank in difficulty.

And that has actually been the case more or less throughout ... and the Bank of England has acted as the co-ordinator and the central operator of a rescue system, rather than doing it all by itself.

More recently, the willingness of the banks to get together to bail out and support their colleagues has actually been diminishing with the more competitive system we now have. Actually now the fund to bail out or to provide any large scale support system for the banks has to come from the taxpayer.

The central bank was an institution that was already in existence, that now could act as agent for the government, combined with what we call fiscal policy, in bringing about full employment, price stability and so on. This became really their dominant or prime function from the end of the Second World War probably up until the 1970s. It's really the exercise of monetary policy which becomes the overriding objective. The older ones of lender of last resort, managing the note issue, being banker to government, really slide back into the background.