The study was conducted to evaluate the percentage rate of bunch rot by planting year and the productivity of oil palm in the highlands. The research was conducted on the plant area yielded by survey method at Kebun Bah Birung Ulu Sidamanik Subdistrict Simalungun Regency. The study was conducted in August 2014 with a height of 648 - 1087 meters above sea level located on Longitude: 2o 52 '08.70' 'N - 99o 00' 14.96'' T and Latitude: 2o 46 '12.59' 'U-98o 56 ' 03.63 '' Q. This research was conducted by collecting data such as An Overview of Biru Ulu Garden of PTPN. IV, the production of fresh fruit bunches per block per year of planting: Actual production (tons/ha) for the 1996, 2004, 2005 and 2006 cropping periods and the number of staples per five years was also used in the determination of palm oil grade and attack percentage data bunch rot) and fruit parthenocarpy in Garden Bah Birung Ulu, PT Perkebunan Nusantara IV, Sidamanik Subdistrict, Simalungun Regency, North Sumatra Province. Research Results Show Oil palms at 4 - 9 years old are still attacked by rotting fruit, but the percentage of attacks tends to decrease with the age of oil palm plantations. The percentage of fruits shipped to the palm oil mill at 4 - 5 year olds is very low and tends to increase fruit rot and parthenocarpi attacks with increasing altitude of the plant site. bunch diseases commonly caused by Marasmius palmivorus also affect the low productivity of plants in the highlands