High-alumina basalts in the convergent zone are classified into: high-, medium- and low-Na type. The high-Na, high-alumina basalts occur in arcs without low-alkali tholeiites, where younger and warmer oceanic lithospheres are subducting. The low-Na, high-alumina basalts occur in arcs where, on the contrary, older and cooler plates are descending and occur also in arcs with extensional tectonics, even though younger lithospheres are underthrusting. A good correlation is observed between the Na 2O content of high-alumina basalts and the age of the subducting lithosphere. This suggests that generation of high-alumina basalt magma is controlled by the nature of the descending plate.