The study of the identity preservation of the Kui ethnic group was conducted in two villages, namely: Ta Khian village in Samrongthap sub-district, Samrongthap district, Surin province, Thailand; and Vialveng village in Sook sub-district, Prasat Sombor district, Kampong Thom province, Cambodia. Despite the fact that these two locations have experienced socio-cultural developments in accordance with natural contexts, they have managed to preserve their ethnic identities, beliefs and rituals. For instance, the Kui ethnic group in Thailand conducts the “Kelmor”and “Yaju Phoju” rituals annually with participants wearing black clothes. They also use their ethnic language in daily communication. Those in Cambodia still worship their ancestral spirits called “Aria Niata” and organize the annual Prawaikoon fight. The main factor contributing to this successful preservation of identities is that the two communities are determined and resolute in safeguarding their heritage. This can be observed by investigating eight indicators, namely:collective responsibility, adaptation to modern times, pride in their ethnic language, faith in their ethnic lifestyle, collective learning, adaptation for survival, strong culture, and confidence in their natural environment