Spatial navigation and episodic memory follow parallel developmental trajectories, perhaps due to the critical role of the hippocampus in both. In adults, the segmentation of continuous experience into discrete events is guided by environmental boundaries such as walls and doors. To investigate the cognitive development of this interaction, we asked whether boundaries influence children's episodic sequence memory similarly to adults and whether a change in children's boundary representations is reflected in a corresponding developmental change in their episodic memory. Children from 3 to 7 years of age re-enacted a sequence of three discrete hiding events within a room containing a boundary. First, we confirmed that, like adults, children's memory of event sequences was affected by the crossing of a spatial boundary. Furthermore, we found that children's changing spatial representations influence their episodic memory development. As in spatial navigation, which relies heavily on 3D boundaries and develops to flexibly include other boundary types, younger children’s episodic memory sequence was only guided by 3D boundaries and gradually included a row of objects and 2D line. By demonstrating the influence of spatial boundaries on children's episodic memory, as well as the concurrent development both spatial and event boundary representations, this study supports the account that spatial cognition and episodic memory share are intimately tied in their neurocognitive basis.