This study analyzed how the recently revised Korean early childhood curriculum describes and discusses sustainability through a critical perspective using posthumanism to destabilize anthropocentric thinking and expand the concept of sustainability. The notion of sustainability described in the General Guidelines and Commentaries of the Korean Early Childhood Curriculum reveal limitations and the potential of the ontological, epistemological, and ethical foundations which serve as the basis of early childhood education. While sustainability was expressed as a new value from which the curriculum stems, it was presented as traditional nature, resource conservation, and raising animals and plants based on human-centered thinking written as educational content. However, through the vison of an educated person of the curriculum, children were found to be relational beings, and in everyday encounters they influenced and interacted with various more-than-human others; there was room for the interpretation that not only children but also other beings exert agency. We live entangled with multiple species. This implies that early childhood pedagogy has the potential to broaden understanding and practice and generate vigorous debate on sustainability.