Potential application of elementary excitation in semiconductor quantum dot to quantum computation is discussed. We propose a scalable hardware and all optical implementation of a logic gate that exploits the discrete nature of electron-hole states and their well-concentrated oscillator strength for ultrafast gate operation. A multiple-bit gate function is based on the nearest neighbour dipole-dipole coupling. Rabi population oscillation and long-lived coherence of an excitonic two-level system in an isolated InxGa1-xAs quantum dot guarantees quantum gate functions. Technologies that will realize and facilitate the exciton quantum computing are discussed.