Since 2008, the Presidential Committee on Library and Information has conducted 'National Library Management Evaluation,' and almost all of the public libraries have participated in the evaluation. In order to find the effect of the Evaluation on the public libraries, this study analyzed four years of the performance scores (2010~2013) during the period of the <TEX>$1^{st}$</TEX> National Library Development Plan 2009~2013, which used the same measurement, were analyzed by the size groups and regions. The results indicated positive effect on the quality of the internal process such as planning and collection building. Yet attainment gab remains between metropolitan and the other regions, and also different relationship exists between input and attainment among the public library size groups. It suggested the policy development considering the library size and the regional difference.