The emergence of the Minister of Education and Culture Regulation No. 23 of 2017 (Permendikbud of 23/2017 about Day of School) made Nahdlatul Ulama reject reason to feel threatened by the policy. This is not only because of Madrasah Diniyah owned by NU would be undermined its existence but also issues of NU’s ideals aimed at keeping a typical Islamic tradition NU archipelago through Madrasah Diniyah education institutions. Rejection conducted by NU then led the struggle by NU through the creation of the Presidential Decree Number 87 the Year 2017 on Strengthening the Character Education (Perpres 87/2017). This analysis study is a qualitative study using the interest group theory perspective that explains how the strategy and the strength of NU as CSOs in a bargaining position are strong. The findings, in the struggle, NU managed to put its interests in the regulation after negotiating with relevant parties.