Credibility is the most important ability of central bank,which has a great significance for central bank to guide the public expectations and to promote the effectiveness of performing their duties.This paper designs an evaluation index system of central bank's credibility according to the influencing factors firstly,and makes use of principal component analysis to build the central bank's credibility index.Then,this article uses Sys-GMM dynamic panel data model to make empirical studies on the relationship between credibility and the ultimate goals of monetary policy for 14 developed and developing countries and regions' central banks.Research shows that the central bank credibility has significant negative correlation relationship with the inflation rate,which means that the more credibility,the more conducive for the central bank to control inflation; central bank credibility has significant positive correlation relationship with the financial stability,which means that improving the central bank's credibility will help the central bank achieve the policy objectives of maintaining financial stability.Therefore,central bank should focus on improving the credibility to improve the effectiveness of monetary policy tools,and to achieve the policy objectives of stabilizing prices and maintaining financial stability.