Annual ryegrass (Lolium multiflorum Lam.) cultivar Sabalan, was evaluated between april 1981 and 1982. The trial was carried out at the Remehue Experimental Station (INIA), in the X Region of Chile. The objective was to evaluate the effect of different N levels and application frequencies upon initial population, dry matter yield, total protein content and in vitro D.M. digestibility. Seeding rate was 25 kg/ha, following a patato crop. The base fertilization was 79 kg P and 42 kg K/ha, as superphosphate and potassium sulphate, respectively, applied at the establishment. A split-plot design, with three replications, was used. Nitrogen levels (30-60-120 and 240 kg/ha/year) were the main plots, and the application form (all the N early in autumn; 50% early in autumn and 50% late in winter; 50% early in autumn and the other 50% divided, after every cutting) were the subdivided plots. Dry matter yield increased from 11.0 to 19.2 ton/ha/year with N30 and N240, respectively (P < 0.05) Total protein percentage and in vitro D.M. digestibility were not modified when N levels were increased regardless of the application form, within the same date of cutting, but varied when different phenological stages at cutting were compared. Total protein yield increased from 388 to 644 kg/ha (in the December cut), when the N dose varied from 30 to 240 kg/ha/year, respectively.