This study analyzes the thermal alteration observed in the burned human bones (C316) excavated from the Dobashi site in Agano City, Niigata Prefecture, dating to the early phase of the Late Jomon period. The C316 remains consist of a single, complete skeleton that had been cremated and subsequently reburied in a pit. The limb bones were intentionally arranged in a distinctive manner, with the right and left humeri placed symmetrically. The individual is estimated to have been an adult to middle-aged male, and evidence of tooth extraction was observed in the right maxillary lateral incisor and canine region. Detailed observation and analysis focused on the shrinkage and deformation of the limb bones, as well as fractures on the bone surfaces caused by thermal exposure. Bone shrinkage occurs during the early stages of thermal alteration, and the degree of shrinkage was found to vary. In particular, shrinkage was inferred to be greater in width and thickness than in length. Comparative analysis from a forensic anthropological perspective revealed that the patterns of bone deformation and fracturing closely resembled those observed in burned bodies with soft tissue still attached. These findings suggest that the C316 individual was burned relatively soon after death, likely through a high-temperature cremation process that thoroughly reduced the body. The C316 remains demonstrate that even burned bones, which have traditionally been considered limited in informational value, can yield diverse and significant insights, highlighting their importance as anthropological material.