The objective of this study was to evaluate lignin and phosphorus content in a Marandu-grass pasture managed under 3 heights of pasture. The pastures were managed by beef steers grazing under continuous stocking. Evaluations of litter decomposition occurred in 2011, at Jaboticabal, SP, Brazil. The litter bag technique was used to evaluate the decomposition of senescent plant material. Incubation times were 4, 8, 16, 32, 64, 128 and 256 d. Nylon bags were used. At the end of each incubation period, the bags were and analyzed. The lignin and phosphorus content was analyzed and compared using Proc Mixed from SAS. Polynomial models were used to fit the curves for each pasture stubble height according to incubation times. A significant linear increase in litter lignin with increasing pasture stubble height was observed in the litter incubated (P < 0.01), with means of 16.32, 18.50, and 19.84%, respectively, for pasture stubble heights 15, 25, and 35 cm. A relative increase in litter lignin (67%) with decomposition time was observed. Since increasing pasture stubble height is associated with stem elongation, hence higher cell-wall and lignin content than leaves, this could explain the positive association observed between litter lignin and pasture stubble height. The magnitude of differences in lignin content according to pasture stubble height is, however, expected to decrease over the course of the incubation period as the relative content of other components becomes progressively lower while lignin remains undecomposed, since it is chemically very insoluble. Since more soluble components, such as cellulose and hemicelluloses, are primarily used by microorganisms as energy source, a relative increase in litter lignin with incubation time is expected. Phosphorus in the incubated litter was 0.02% on average, and did not differ among pasture stubble heights (P > 0.05). The relative increase in litter phosphorus content with incubation time (P < 0.01) was expected. As phosphorus immobilization occurs when C/P ratio is higher than 200, this process prevailed throughout the incubation period, when C/P ratios ranged from 1600 to 825.