Fruit rot disease in coffee plants (Coffea sp.) is caused by pathogenic fungi (Fusarium sp.). Control of coffee berry rot disease can be done by using biological agents in the form of rhizosphere fungi which have antagonistic properties against pathogenic fungi. This study aims to determine the type of fungus from coffee fruit rot and rhizosphere fungi and to determine the ability of rhizosphere fungi to inhibit the growth of pathogenic fungi. The study was conducted in January-April 2020. This study used a completely randomized design (CRD) with 4 treatments and 3 repetitions. Sampling was carried out in a coffee plantation (Coffea sp.) Punggur Kecil Village, Kubu Raya Regency. Fungal isolation was carried out using the dilution method and the antagonist test was carried out using the paired method. Based on the results of the study, there was an inhibition of the growth of the fungus Fusarium sp. JPTK1 and Fusarium sp. JPTK2 by Trichoderma sp. JRTK3 with the highest percentage of antagonists were 37.12% and 70.48%, respectively.Keywords: fruit rot disease; biological agents; coffee; rhizosphere fungiAbstrakPenyakit busuk buah pada tanaman kopi (Coffea sp.) disebabkan oleh jamur patogen (Fusarium sp.). Pengendalian penyakit busuk buah kopi dapat dilakukan dengan menggunakan agen hayati berupa jamur rizosfer yang memiliki sifat antagonis terhadap jamur patogen. Penelitian ini bertujuan untuk mengetahui jenis jamur dari busuk buah kopi dan jamur rizosfer serta untuk mengetahui kemampuan jamur rizosfer dalam menghambat pertumbuhan jamur patogen. Penelitian dilakukan pada bulan Januari-April 2020. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 3 kali pengulangan. Pengambilan sampel dilakukan di perkebunan kopi (Coffea sp.) Desa Punggur Kecil Kabupaten Kubu Raya. Isolasi jamur dilakukan dengan metode pengenceran dan uji antagonis dilakukan dengan metode berpasangan. Berdasarkan hasil penelitian, terjadi penghambatan pertumbuhan jamur Fusarium sp. JPTK1 dan Fusarium sp. JPTK2 oleh Trichoderma sp. JRTK3 dengan persentase antagonis tertinggi masing-masing yaitu 37,12% dan 70,48%. Kata kunci: penyakit busuk buah; agen hayati; kopi; jamur rizosfer.