As the most important federal sources of fund for American public libraries, the IMLS has the legal right to grant financial aids, collect data, construct strategy relationship and provide suggestions to the decision makers and other federal agencies about museums, libraries and data services. The Report shows the federal financial guarantee features of American public library. In our country, more laws and regulations should be made to grant fund to public libraries, including the quantity, the scope of use of funds, supervision rules, and under the premise of basic funds, strengthening special funding and incentive funding.