A valve characteristic control apparatus is provided in an internal combustion engine including a variable valve mechanism that can change at the least, among valve characteristics of an exhaust valve, a closing timing of the exhaust valve, and in which a number of injections of fuel is changed during one engine cycle. The valve characteristic control apparatus sets the closing timing of the exhaust valve to a retard side during an engine warming up operation. When setting to the retard side is performed, if two injections are performed, an exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a dual injection use map. On the other hand, if one injection is performed, the exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a single injection use map.