The research was conducted to see the forage production, carry capacity and rotation cycle that was most suitable for grazing cattle in the ecosystem of oil palm plantations. The research was conducted at Tanah Itam Ulu Oil Palm Plantation, Tanah Itam Ulu Village, Lima Puluh District, North Sumatra from January-December 2017. The research used RCBD consisting of 3 x 3 with 3 replications. The first factor is the age of oil palm trees (6, 12 18 years), the second factor is the rotation cycle of forage (40, 50, 60 days). The parameters observed: forage production, cattle capacity, forage nutritional and botanical composition. The research results showed that forage production and carrying capacity had a significantly higher effect (P <0.05) with a harvest interval of 40 days at the location of juvenile oil palm, which was 11,962 kg dry matter /ha/year and carrying capacity was 1.31 AU/ha. Forage quality (protein, NDF and ADF) had no significant effect (P> 0.05). The dominant forage species appeared in almost all observation plots, namely Cyrtococcum and Axonopus. The results of the study concluded that oil palms of 12 years with a harvest rotation of 40 days provided the largest capacity for grazing beef cattle.