The Nias language that records the richness of Nias culture is ke-fo-an. Ke-fo-anis a mixture of five entities originating from nature or the environment that are often used as snacks or cigarettes by residents who live in the geographical area of the Nias archipelago. The five main ke-fo-anentities are fino (betel nut), gambe (gambir leaf), becua (lime), tawuo (betel), and bako (tobacco). The purpose of this study is to describe the syntactic category of the afo-an ecolexicon in the Central Nias Dialect. This research was designed with a mixed methods research approach (qualitative and quantitative). The result shows There are 3 syntactic categories that exist in the afo-an tradition, namely, noun, verb, and adjective categories. Examples of noun categories are the word from madawa 'knife' and the noun phrase cucu wole 'pelocok kinang' which has a syntactic construction, core noun + modifier noun. Furthermore, examples of categories of verbs are such as the original word 'chew' and the phrase mamici 'concealing' which has a syntactic construction, prefix as a modifier element + verb as a core element. Examples of adjective categories are the origins of olombanö 'dizzy' and afoe 'sepat'.