We investigated pressure-induced changes in the coordination environments of Fe²⁺ and Fe³⁺ in basaltic glasses based on the Fe K-edge X-ray absorption fine structure (XAFS) analyses for both XANES and EXAFS regions. Upon compression from 1 bar to ~15 GPa, the Fe²⁺-O bond length remained similar, suggesting that the average coordination number of Fe²⁺ increased from ~5 to 6. On the other hand, the Fe³⁺-O bond was remarkably elongated, which indicates that Fe³⁺changed from 4-fold to 6-fold coordination. Above 15 GPa, both Fe²⁺-O and Fe³⁺-O bond lengths decreased smoothly, suggesting minor changes in their coordination numbers. The data also showed that both Fe²⁺ and Fe³⁺ remained in the high-spin state up to 83 GPa and 60 GPa, respectively, in the basaltic glasses. These compression behaviors of the Fe²⁺-O and Fe³⁺-O bonds support that Fe²⁺ disproportionates into Fe³⁺ and metal Fe in a deep magma ocean.