Abstract. Efendi M, Ardiyanto D, Nudin, Nur M, Nasution T. 2020. Botanical exploration in the Mount Ketambe, Mount Leuser National Park Aceh. Pros Sem Nas Masy Biodiv Indon 6: 558-563. Cibodas Botanic Garden (CBG) main duty is conducting ex-situ conservation of Indonesian mountain flora, especially rare species and potentially economic plants. In order to support this duty, botanical exploration was done for collection enrichment in Mount Ketambe forest, Mount Leuser National Park (MLNP) Aceh. This study aims to identify species and evaluate survival rate of exploration collection plant in CBG. Survey method was conducted for specimen collection at 835-1261 above sea level in Mount Ketambe of MLNP. Survival rate data was recorded in Nursery Unit of CBG for one year. In this exploration, was collected about 258 specimens, consist of 171 collection numbers and 56 families, at least 9% new collections for CBG, namely Antiaris toxicaria, Ardisia sessilifolia, Begonia verecunda, B. laruei, Gynochtodes coriacea, Medusanthera laxiflora, Riparosa javaniva, Dialium cf kunstleri, Aporosa grandistipula, Tainia obpandurata, Leptonychia caudata, Chionanthus grandifolius, Polyalthia cauliflora, Dehaasia sumatrana, Persea glabra, and Diospyros javanica, while Paraboea leuserensis, B. verecunda, B. leuserensis, Illicium sumatranum dan Ardisia cf sessilifolia well-known as endemic for Sumatera. Survival rate of plant collection was 74%, showed compatibility of microclimate between a submontane zone of Mount Ketambe and CBG area. In the future, plant collection will be the source of germplasm to develop for medicinal, ornamental, food, cosmetic, or timber.