This study aims to generate and measure the value of the validity and practicality of the E-LKPD buffer solution. E-LKPD is prepared based on a guided inquiry model. The type of research used is Research and Development using the plomp development model. The research instrument was a content and construct validity sheet as well as a practicality questionnaire. The E-LKPD was validated by 2 chemistry lecturers at Padang State University and 1 chemistry teacher, as well as a practicality test (field test) through 15 students of class XI SMAN 4 Padang. The results of the study found that the guided inquiry-based worksheets had a high level of category validity (V=0.91) and the practicality level of students with a very practical category on the score (NP=90%). This research is recommended for further research in terms of testing the effectiveness of the products that have been developed.Keywords: Guided Inquiry, E-LKPD, Buffer Solution, Plomp ABSTRAKPenelitian ini bertujuan untuk menghasilkan serta mengukur nilai validitas dan praktikalitasE-LKPD larutan penyangga. E-LKPD disusun berdasarkan model inkuiri terbimbing. Jenis penelitian yang digunakan ialah Reseacrh and Development memakai model pengembangan plomp. Instrumen penelitian berupa lembar validitas konten dan konstruk serta angket praktikalitas. E-LKPD divalidasi oleh 2 orang dosen kimia Universitas Negeri Padang dan 1 orang guru kimia, serta uji kepraktisan (uji lapangan) melalui 15 orang siswa kelas XI SMAN 4 Padang. Hasil penelitian menemukan bahwa LKPD berbasis inkuiri terbimbing memiliki tingkat validitas kategori tinggi (V=0,91) dan tingkat kepraktisan siswa dengan kategori sangat praktis pada nilai (NP=90%). Penelitian ini direkomendasikan untuk penelitian selanjutnya dalam hal uji efektivitas produk yang telah dikembangkan.Kata Kunci: Inkuiri Terbimbing, E-LKPD, Larutan Penyangga, Plomp.