Li(H2O)(4)B(OH)(4) . 2H(2)O, Li3B5O8(OH)(2), Li(H2O)B2O3(OH) and Li(H2O)(3)B5O6(OH)(4) were synthesized and their dehydration were studied using various thermal analyses and also by examination of their crystal structure and especially the modification of Li+ coordination during dehydration. As expected, the adsorbed water leaves the structure below 100 degrees C; then the structural free water molecules and after that the water molecules coordinated to Li escape. Finally, the OH groups leave the framework. The surrounding of the lithium atoms governs the dehydration process; when its surrounding falls below four, the framework collapses and an amorphous phase is generally obtained. Therefore, there are no relationships between the structure of the anhydrous berates - LiBO2, LiB2O3.5 (or Li2B4O7), LiB5O8 and also LiB3O5 which can be obtained from mixture of two precursors - and the structure of their hydrated precursors.