摘要:现今,全球经济一体化，跨国投资日益频繁和增多。一方面，各国政府在国际资本市场上发行的主权债券日渐增长；另一方面，国与国之间私人和政府投资也越来越频繁。因而产生了对一国基本经济状况和主权信用风险的测量与评级的机构。国际三大评级机构(标准普尔，穆迪，惠誉)是世界公认最有公信力的评级机构，他们运用不同的分析测量方法对各个国家进行评级，帮助国际市场的投资者进行投资。一个国家的分析和测评结果是非常重要的，对国际市场有着很大的影响，然而，历年来国际上频繁出现的主权信用违约事件，令我们不禁怀疑评级机构们对主权信用评级的可信度。

关键词:  主权评级,评级机构,主权债务,债务危机, 国家财政

Abstract:Nowadays, we are living in the century of global economic integration. With the increasing growing of transnational investment, on the one hand, sovereign bonds which issued by government has grew day by days ,on the other hand ,individual and  government investment between countries are becoming more and more frequently , as a result , Agencies which are in charge of estimating a country’s fundamental economic situation were appeared .The three International rating agencies（Standard& Poor's ; Moody's ; Fitch Rating ） are recognized as the most credible rating agencies. They combine with different measuring methods of analysis for each country ratings, helping those investors to invest in the international market. The results of a country's analysis and assessment are very important, witch have great influences on the international market. However, the international sovereign default events frequently appeared in the over years, which make us couldn't help to doubt the results of sovereign rating form those rating agencies.

Key Words: Sovereign rating, Rating Agency, sovereign bond,debt crisis, Public finance

主权信用评估作为一个特殊的行业，其主要作用是警示风险。其独立、客观、准确、公正是其赖以生存生命线。综合上所诉，在多次危机期间的表现，我们发现其一个“+”“-”级别的微调会引起金融恐慌，即使一个业务声明也能引发金融市场的震荡，主权评级的敏感，很多时候令到市场上经常出现评级危机事件，令到投资者越来越觉得主权评级的可信度不高    近年来爆发的主权信用危机事件在市场上闹得沸沸扬扬，希腊主权违约时间的影响也仍未消除，继而，国际三大国际机构又逐一下调爱尔兰，西班牙，葡萄牙等多国的主权信用评级。尽管在2011年12月召开了紧急欧盟峰会，但结果也没有使评级机构的降级行为有所停止。

    评级危机事件令到投资者们心寒，主权信用评级的可信度逐年下滑，业内专业人士应该要进行反省。评级行业是新兴行业，评级机构之间需要更多的竞争，评级行为业需要更大程度的透明度，否则评级的危机事件只会接踵而至，评级业的发展也会稍纵即逝，成为昙花一现的行业。