PURPOSE: To obtain the high-strength and heat-resistant spring copper alloy excellent in spring properties by specifying the compsn. constituted of Zn, Ni, Mn, Si and Cu.

CONSTITUTION: The high-strength and heat-resistant spring copper alloy contains, by weight, 10 to 30% Zn, 5 to 25% Ni, 0.001 to 1% Mn and 0.01 to 1% Si, if required, furthermore contains as auxiliary components, 0.01 to 2% of one or more kinds among Te, Cr, Co, Zr, V, Be, Cd, As, P, Sn, Fe, Mg, In, Ti and Al and the balance Cu with inevitable impurities, of which Mn, Si, etc., are added to a Cu-Zn-Ni series-nickel silver alloy to improve the characteristics. The alloy has excellent strength, spring properties and heat resistance and is suitable as the spring material for connectors, terminals, relays, switches or the like.