The aim of this study was to determine individual orangutan home ranges and core areas and identify overlapping areas among individuals. The research was conducted over 34 months, at Cabang Panti Research Station, Gunung Palung National Park, West Kalimantan. Observations were conducted by focal animal sampling, were taken 30 minutes points during focal follows. Data results show that the average daily journey length of a female orangutan at Cabang Panti was 762 meters and the average length of a male was 748 meters. Based on Kernel analysis, it was determined that a female orangutan home range area occupies 33,6% of the research area on average, roughly quivalent to a male's home range, which occupies 36,9% of the research area. Meanwhile, the average female orangutan core area was 36 ha and average male core area was 43 ha. Among female orangutans, Beth was the adult female who had the largest overlap area with the male ranges, wheareas Codet (a flanged male) and Zorro (an unflanged male) had the largest overlap areas with the female ranges.