A low-temperature bonding technique is utilized for bonding different kinds of materials together. However, it is still challenging to achieve sufficient bonding strength at lower temperatures. To overcome the limitation of low-temperature bonding, we must clarify the bonding mechanism at the functional group level. Nevertheless, no comprehensive explanation for the material dependence of the bonding strength has been demonstrated. In the present study, the bonding strength between various metal oxides and silica (SiO 2 ) modified with hydroxyl (Si−OH) or amino groups (Si−NH 2 ) is clarified. Modification with Si−NH 2 to SiO 2 surfaces improved the bonding strength to SiO 2 , TiO 2 , SnO 2 , MnO 2 , WO 3 , and CrO 3 , but it rather deteriorated the strength to NiO, Al 2 O 3 , and MgO. The material dependence of the bonding strength originated from the number of covalent bonds formed between SiO 2 and metal oxides as well as their bond energy. The reactivity of the bond formation between the metal oxides and Si−NH 2 -modified SiO 2 cannot be explained by the areal density of the hydroxyl groups on metal oxides (M−OH), which is the most general expectation. In contrast, we found that the reactivity of Si−NH 2 was well explained by the acidity/basicity of M− OH, which has rarely been considered in the field of low-temperature bonding.