This research was aim to identification the utilization of cow manure to improving the average of height, midrib, stems diameter, and leave area on the seddlings of oil palm on main nursery. This research was conducted on Bau Tunggal Village North Labuhanbatu District on March until June 2023. This research used blocked randomized design consisted of 6 level those are P0 = 100 g/polybag, P1 = 200 g/polybag, P2 = 300g/polybag, P3=400 g/polybag, P4=500 g/polybag, P6=600 g/polybag and each treatment have 3 repetition. The results showed the used of cow manure could improving the growth of oil palm seedlings at main nursery. P5 or 500g/polybag have the highest growth of oil palm seedlings and could support the height by 6 cm, midrib by 2 cm, stem diameter by 2 cm and leave area by 9 cm compared to control.Keywords: Compost, Oil palm, PlantINTISARITujuan penelitian ini untuk mengidentifikasi pemanfaatan kotoran sapi dalam meningkatkan rata-rata tinggi, pelepah, diameter batang, dan luas daun pembibitan utama kelapa sawit. Riset ini telah dilakukan di Desa Batu Tunggal Kabupaten Labuhan Batu Utara pada bulan maret hingga Juni 2023. Percobaan disusun berdasarkan rancangan acak kelompok yang terdiri dari 6 dosis yaitu P0 = kotoran sapi(100 g/polybag),P1 = kotoran sapi (200 g/polybag),P2 = kotoran sapi (300 g/polybag),P3 = kotoran sapi (400 g/polybag),P4 = kotoran sapi (500 g/polybag),P5 = kotoran sapi (600 g/polybag) dengan 3 ulangan. Hasil dari penelitian ini melaporkan bahwa pemberian kotoran sapi dapat meningkatka. Peetumbuhan bibit utama sawit. Kotoran sapi dengan dosis P5 ( 600 g/ polybag ) mampu mendukung pertumbuhan tinggi bibit sebesar 6 cm, jumlah pelepah sebanyak 2 pelepah, diameter batang sebesar 2 cm dan luas daun sebesar 9 cm di banding tanpa pemberian kotoran sapi. Kata kunci: Kompos, Sawit, Tanaman