Quantum computation and quantum information processing, lying in the interdisciplinary field of computer science, mathematics and physics, is developing rapidly in recent years. This emerging and exciting field exploits quantum features in performing various information tasks, and opens new avenue for our information era. Quantum informatics exhibits many facets, ranging from quantum simulation to quantum computation, and including quantum cryptography, quantum communication and it is expected to solve complex problems more effciently than any method within the capabilities of classical scenario. The special issue "Quantum computation and quantum information processing" provides a forum for dissemination of recent results and reviews about various aspects of quantum computation and quantum information. We hope it may contribute to the wider exploitation of quantum sciences and technology in mainstream information engineering. We are grateful to both the authors and referees for their contributions to this special issue. We are also grateful to the chief editor of IJSI, Academician Ruqian Lu, for initiating this project.