Rice is a very important crop for humans because more than half of the world’s population including Indonesia depends on these plants as a source of food. Diseases that often attack rice plants are bacterial leaf blight, this disease can reduce rice production by up to 60%. Control of bacterial leaf blight in addition to using chemicals can also use biological agents, one of which is Paenibacillus polymyxa. Testing of biological control applications begins with inoculation of Xanthomonas oryzae bacteria on ciherang rice seeds 9 days after planting (DAP). Planting rice using Randomized Block Design using biological control Paenibacillus polymyxa consists of four treatments, Control (P0), 2,5 ml l^-1 (P1), 5 ml l^-1 (P2), and 7,5 ml l^-1 (P3).  The biological control application is carried out on seeds, 10 DAP, 2 week after planting (WAP), and 4 WAP. Observations were made once a week to observe the rice growth and intensity of the disease. Observations were made in the vegetative phase. The results of the Paenibacillus polymyxa biological control test can reduce the level of bacterial leaf blight attack even though the difference in each treatment is not significantly different. The recommended concentration of Paenibacillus polymyxa biological control is 7,5 ml l^-1. This concentration can reduce the level of bacterial leaf blight attack in the vegetative phase.