Abstrak.Suatu penelitian tentang efektivitas mikoriza arbuskula terhadap kandungan nutrisi rumput setaria (Setaria sphacelata) telah dilakukan di Laboratorium Lapangan Peternakan (LLP) yang terletak di Jalan Utama Gampong Rukoh dan Laboratorium Ilmu Nutrisi dan Teknologi Pakan Prodi Peternakan, Fakultas Pertanian, Universitas Syiah Kualamulai dari bulan Januari 2017 hingga Juli 2017. Penelitian bertujuan untuk mengetahui kandungan protein kasar dan serat kasar rumput setaria yang diberi mikoriza arbuskula. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) yang terdiri atas 4 perlakuan dengan 5 ulangan. Perlakuan L0 adalah perlakuan kontrol/tanpa pemberian mikoriza arbuskula, perlakuan L1 adalah perlakuan dengan pemberian 5 gr mikoriza arbuskula per rumpun, perlakuan L2 adalah perlakuan dengan pemberian 10 gr mikoriza arbuskula per rumpun, sedangkan perlakuan L3 adalah perlakuan dengan pemberian 15 gr mikoriza arbuskula per rumpun. Parameter yang diukur adalah kadar protein kasar dan serat kasar. Hasil penelitian menunjukkan bahwa aplikasi mikoriza arbuskula berpengaruh sangat nyata (P0,01) terhadap kandungan protein kasar dan serat kasar rumput setaria.The Crude Protein and Crude Fiber Content of Setaria sphacelata with Different Level of Arbuscular Mychorrizal ApplicationAbstract. A research regarding the effectivity of arbuscular mycorrhizal applied on setaria (Setaria sphacelata) grass was conducted at Field Laboratory Peternakan (LLP) located onJalan UtamaGampong Rukoh and at Nutritional ScienceandFeed Technology Laboratory, Department of Animal Husbandry Faculty of Agriculture Syiah Kuala University. The research had been conducted from January to July 2017. The objective of the research was to findthe crude protein and crude fiber content of Setaria sphacelataforage plant on which applied with different level of arbuscular mychorrizal. Completely Randomized Design was used in this research consists of four treatments (L0 = control/0 gr arbuscular mycorrhizal applied per clumps, L1 = 5 gr arbuscular mycorrhizal applied per clumps, L2 = 10 gr arbuscular mycorrhizal applied per clumps, and L3 = 15 gr arbuscular mycorrhizal applied per clumps), and five replications. Crude protein and crude fiber content were the parameter estimated. Statistical analysis showed that there was highly significant effect (P0,01) caused bythe treatments on crude protein and crude fiber content. The conclusion was that the different level of arbuscular mycorrhizal applied on setaria grass indicated to different result.