Castanopsis tungurrut (Blume) A.DC. (Fagaceae) is an Indonesian native plant species with limited spatial distribution; it is found only in Java, Kalimantan, and Sumatera in lower montane to submontane forests. This species has been classified as endangered by the IUCN, necessitating collection of more information on its habitat and environmental preferences before embarking on conservation planning. Studies on the species' natural habitat are scarce. This study aims to identify the environmental factors (edaphic + climatic factors) influencing the distribution of C. tungurrut along an altitudinal gradient in the Cibodas Biosphere Reserve. The nested plot method was applied to assess the forest vegetation at an altitudinal range of ca. 750–1800 m asl. Environmental factors were measured using portable equipment and through laboratory analysis. Ordination technique using canonical correspondence analysis (CCA) was utilised to pinpoint the environmental factors influencing the species' distribution based on basal area. CCA showed temperature to be the most limiting factor affecting the distribution. Edaphic factors – cation exchange capacity, content of carbon, nitrogen, phosphorus, and potassium, and soil pH – had less influence. Thus, it can be inferred that dependence of C. tungurrut on temperature determines its distribution pattern in its natural habitat, similar to Ostodes paniculata and Sloanea sigun. In contrast, the distribution of Castanopsis javanica, Castanopsis argentea, Schima wallichii, Altingia excelsa, Dacrycarpus imbricatus, Cestrum aurantiacum, and Castanopsis acuminatissima was found to be more influenced by edaphic factors than by climatic factors.