Orangutans are land mammals with slow growth and reproduction. Orangutans are semi-solitary animals, social interactions occur between males and females when they want to mate, mothers and children because they have a close relationship. The Panti Branch Research Station (CPRS) of Gunung Palung National Park (GPNP) is known to often find orangutan mother and child pairs and is a natural habitat for orangutans. This research aimed to examine the social behavior of mothers and child orangutan infant-level at CPRS. The survey method was used to search for orangutans, selecting samples using a purposive sampling technique. The research sample was limited to mother and child orangutan infant-level. Orangutan observation and data collection used the focal animal sampling method, data recording used the continuous recording technique at 5-minute intervals. The results of data that the response and treatment of the mother orangutan to her baby shows that the relationship between mother and child orangutans at SRCP is functioning as it should as wild animals in the wild. The behavior of orangutan mothers towards their babies is included in affiliative behavior, however, they tend to behave aggressively when they meet humans. As orangutans get older, children become increasingly distant from their mothers. Keywords: Cabang Panti, mather and infant, orangutan, social behavior Abstrak Orangutan merupakan mamalia darat dengan pertumbuhan dan perkembangbiakan yang lambat. Orangutan termasuk ke dalam satwa semi soliter, interaksi sosial terjadi pada jantan dan betina apabila ingin kawin, ibu dan anak karena memiliki hubungan erat. Stasiun Riset Cabang Panti (SRCP) Taman Nasional Gunung Palung (TNGP) diketahui sering ditemukan pasangan ibu dan anak orangutan dan menjadi habitat alami orangutan. Tujuan penelitian ini mengkaji perilaku sosial ibu dan anak orangutan tingkat infant (bayi) di SRCP. Metode survei digunakan untuk pencarian orangutan, penentuan sampel menggunakan teknik purposive sampling. Sampel penelitian dibatasi pada pasangan ibu dan anak orangutan tingkat infant (bayi). Pengamatan orangutan dan pengambilan data menggunakan metode focal animal sampling, pencatatan data menggunakan teknik continues recording dengan interval waktu 5 menit. Hasil analisis data menunjukan bahwa respon dan perlakuan ibu orangutan kepada bayinya menunjukan hubungan induk dan anak orangutan di SRCP berjalan sebagaimana mestinya sebagai satwa liar di alam liar. Perilaku ibu orangutan terhadap bayinya termasuk dalam perilaku afiliatif, akan tetapi cenderung berperilaku agresif apabila bertemu manusia. Seiring bertambahnya usia orangutan anak akan semakin berjarak dengan ibunya. Kata kunci: Cabang Panti, ibu dan anak, orangutan, perilaku sosial