Abstrak Penelitin ini merupakan penelitian yang bertujuan untuk mengetahui efektifitas buku penghubung berbasis online pada kegiatan shalat siswa kelas 3 MI Sunan Ampel Bangsal Mojokerto. Penetilitian merupakan jenis penelitian kuantitatif deskriptif. Dengan melibatkan responden siswa kelas 3 MI Sunan Ampel dan sample penelitian sebanyak 30 responden yang ditentukan melalui tehnik simple random sampling. Hasil dari penelitian ini menunjukan total item sebesar 2367.5 dengan hasil skor nilai rata-rata sebesar 79. Sehingga buku penghubung berbasis online dikatakan efektif pada kegiatan shalat siswa kelas 3 MI Sunan Ampel Bangsal Mojokerto. Kata Kunci: Efektifitas, Buku penghubung berbasis online, Kegiatan shalat Abstract This research is a research that aims to ensure the effectiveness of online-based liaison books in the prayer activities of the 3rd grade students of MI Sunan Ampel Bangsal Mojokerto. Research is a descriptive quantitative research type. With the third grade student respondents at MI Sunan Ampel and a research sample of 30 respondents who were determined through simple random sampling technique. The results of this study indicate a total item of 2367.5 with an average result score of 79. So that the online-based liaison book is said to be effective in the prayer activities of the 3rd grade students of MI Sunan Ampel Bangsal Mojokerto. Keywords: Effectiveness, Online-based connecting book, Prayer activities