To determine the nature of a salt, we need to consider the nature of its constituent ions. In Na2HPO3, we have the sodium ion (Na+) and the hydrogen phosphite ion (HPO3^2-).

Sodium is a metal and forms basic oxides. The hydrogen phosphite ion is derived from a weak acid (phosphorous acid, H3PO3) and a strong base (sodium hydroxide, NaOH). When a weak acid reacts with a strong base, the resulting salt is basic.

Therefore, Na2HPO3 is a basic salt.