The purpose of this study was to evaluate the quality of Marandu grass (Brachiaria brizantha) haylage according to different dry matter (DM) contents in storage. The design adopted was completely randomized with four treatments and five replications. The treatments were DM contents of the plant at the moment of storage (in natura, 30–40, 40–50 and 50–60% DM). The analyses to assess the quality of the haylage were performed after 90 days of storage. The chemical composition, microbiological population, gas quantification, pH, N-NH3, volatile fatty acids, soluble carbohydrates (CHO) and the aerobic stability were evaluated. The means were compared through the Tukey's test and linear regression. The treatment with 50–60% DM presented the highest DM and CHO contents which were 563.8 and 42.0 g/kg, respectively. There was a higher presence of oxygen in the haylage of in natura material, which was 4.8%. There was no difference between treatments for the population of lactic acid bacteria; however, the treatment with 50–60% DM had the highest concentration of enterobacteria. The haylage with 30–40% DM and 50–60% DM presented high concentrations of acetic acid. There was no break in aerobic stability for any treatment within 120 h after opening the bales. There was a smaller amount of N-NH3 in treatments with 40–50% DM and 50–60% DM. The Marandu grass with a DM content of 50–60% for haylage making demonstrated better quality characterization of conserved forage.