Penelitian ini bertujuan agar mengetahui pengaruh jenis isolat rizobakteri asal Kecamatan Pegasing Kabupaten Aceh Tengah terhadap pertumbuhan patogen Phytopthora capsici dan perannya sebagai pemacu pertumbuhan tanaman. Penelitian ini dilaksanakan di Laboratorium Ilmu dan Teknologi Benih Jurusan Agroteknologi Fakultas Pertanian dan Laboratorium Biologi FKIP Universitas syiah kuala, dilaksanakan mulai bulan Mei sampai Desember 2022. Rancangan yang digunakan pada penelitian ini ialah Rancangan Acak Lengkap (RAL) pola non faktorial terdiri dari 9 perlakuan isolat rizobakteri dengan 3 ulangan, sehingga diperoleh 27 satuan percobaan. Isolat rizobakteri PM 6/3 memiliki kemampuan daya hambat terbaik dengan nilai 85,77% dan mempunyai laju penghambatan pertumbuhan koloni patogen terbaik dengan nilai 0,31 mm . Semua isolat rizobakteri yang diuji tidak mampu menghasilkan senyawa HCN yang ditandai dengan kertas saring tidak mengalami perubahan warna. Isolat rizobakteri PM 7/1 memiliki kemampuan memproduksi hormon IAA tertinggi dengan nilai 0,62 µg mI . Semua isolat rizobakteri yang diuji berpotensi melarutkan fosfat (P) yang ditandai dengan terbentuknya zona beningn (halozone) disekitar suspensi yang berisi isolat rizobakteri. Jenis isolat rizobakteri yang diuji mampu bereaksi gram positif PM 6/1, PM 6/2, PM 6/3, PM 8/1, PM 8/2 dan PM 8/3, serta isolat rizobakteri PM 7/1, PM 7/2 dan PM 7/3 bereaksi gram negatif.In Vitro Test of Rhizobacteria Isolate from Central Aceh District on Growth of Pathogen Phytophthora capsiciThe aim of this research was to determine the effect of the type of rhizobacterial isolate from Pegasing District, Central Aceh Regency on the growth of the pathogen Phytopthora capsici and its role as a promoter of plant growth. This research was conducted at the Laboratory of Seed Science and Technology, Department of Agrotechnology, Faculty of Agriculture and the Biology Laboratory of FKIP, University of Syiah Kuala, from May to December 2022.This study used a completely randomized design (CRD) with a non factorial pattern consisting of 9 treatments of rhizobacterial isolates with 3 replications, resulting in 27 experimental units. Isolate rhizobacteria PM 6/3 had the best inhibition ability with a value of 85.77% and had the best inhibition rate of growth of pathogenic colonies with a value of 0,31 mm . All rhizobacterial isolates tested were unable to produce HCN compounds which were marked on filter paper that did not change color. Isolate rhizobacteria PM 7/1 had the highest ability to produce IAA hormone with a value of 0,62 µg mI . All rhizobacterial isolates tested had the potential to dissolve phosphate (P) which was indicated by the formation of a clear zone around the suspension containing rhizobacterial isolates. The types of rhizobacterial isolates tested were able to react gram positively to PM 6/1, PM 6/2, PM 6/3, PM 8/1, PM 8/2 and PM 8/3, as well as rhizobacterial isolates PM 7/1, PM 7/ 2 and PM 7/3 react gram negatively.