The objective of this study was to evaluate the effects of different soluble carbohydrates (starch and neutral detergent-soluble fiber - NDSF) types and proportions on ruminal degradability and fermentation parameters in crossbred sheep. Six ruminally cannulated male sheep (Santa Ines × Dorper; 35 ± 0.9 kg BW) were housed in metabolism cages, assigned to a replicated 3 × 3 Latin square design. During 63 d, lambs were fed with 3 isonitrogenous and isoenergetic diets (30% corn silage and 70% concentrate): D1 - high starch concentration (26.6%) and low NDSF concentrations (13.4%); D2 - similar concentrations (18.4%) of starch and NDSF, D3 - high NDSF concentration (24.3%) and low starch concentration (8.3%). To formulate concentrates were used corn, citrus pulp (only orange), soybean hulls, soybean meal, sunflower meal, sunflower oil and urea. The dried ground samples were incubated in nylon bags (7 × 14 cm) into the rumen for 3, 6, 12, 24, 48 and 72 h. The fraction “a” was determined by washing the bags in water and the residue after 72 h incubation was considered the fraction “c.” The potential and effective degradabilities were calculated with the models: P = a + b (1 - e^kt), and P = a + b * [k / (k + K_p)], respectively. Ammonia nitrogen (AN), volatile fatty acids (VFA), and pH were determined at 1 h pre-prandial and 0, 1, 2, 4, 6, and 8 h after morning feeding. Data were analyzed using the MIXED procedure of SAS, with repeated measures. The degradation parameters were not affected by diets (P > 0.05). The corn OM presented potential degradability of 81.7% and degradation rate of 10.7%/h, while citrus pulp OM showed 90.5% and 8.4%/h, respectively. Total VFA, acetic, propionic and butyric acids were unaffected (P > 0.05) by dietary treatments (79.3, 50.9, 18.8, and 9.6 mM, respectively). The diets did not alter ruminal pH values (averaging 6.3; P > 0.05), but AN concentrations (15.87%) were higher (P < 0.05) in D3. Diets with different types and proportions of soluble carbohydrates do not affect neither ruminal degradation kinetics nor VFA concentrations, however the ruminal AN concentration increases in NDSF diets.