Keynote Speech -- Session 1A: Parallel Algorithms and Systems I -- Session 1B: Data Mining and Management -- Session 1C: Distributed Algorithms and Systems -- Session 2A: Fault Tolerance Protocols and Systems -- Session 2B: Sensor Networks and Protocols -- Session 2C: Cluster Systems and Applications -- Session 3A: Parallel Algorithms and Systems II -- Session 3B: Grid Applications and Systems -- Session 3C: Peer-to-Peer and Ad-Hoc Networking -- Session 4A: Grid Scheduling and Algorithms I -- Session 4B: Data Replication and Caching -- Session 4C: Software Engineering and Testing -- Session 5A: Grid Protocols -- Session 5B: Context- ware and Mobile Computing -- Session 5C: Distributed Routing and Switching Protocols I -- Session 6A : Grid Scheduling and Algorithms II -- Session 6B: Cluster Resource Scheduling and Algorithms -- Session 6C: Distributed Routing and Switching Protocols I -- Session 7A: Security I -- Session 7B: High Performance Processing and Applications -- Session 7C: Networking and Protocols I -- Session 8A: Security II -- Session 8B: Artificial Intelligence Systems and Applications -- Session 8C: Networking and Protocols II -- Session 9A: Hardware Architectures and Implementations -- Session 9B: High Performance Computing and Architecture -- Session 9C: Distributed Processing and Architecture.Welcometotheproceedingsofthe2ndInternationalSymposiumonParalleland Distributed Processing and Applications (ISPA2004) which was held in Hong Kong, China, 13–15 December, 2004. With the advance of computer networks and hardware technology, parallel and distributed processing has become a key technology which plays an imp- tant part in determining future research and development activities in many academic and industrial branches. It provides a means to solve computati- ally intensive problems by improving processing speed. It is also the only - ableapproachtobuildinghighlyreliableandinherentlydistributedapplications. ISPA2004 provided a forum for scientists and engineers in academia and ind- try to exchange and discuss their experiences, new ideas, research results, and applications about all aspects of parallel and distributed computing. There was a very large number of paper submissions (361) from 26 countries and regions, including not only Asia and the Paci?c, but also Europe and North America. All submissions were reviewed by at least three program or technical committee members or external reviewers. It was extremely di?cult to select the presentations for the conference because there were so many excellent and interesting submissions. In order to allocate as many papers as possible and keep the high quality of the conference, we ?nally decided to accept 78 regular papers and 38 short papers for oral technical presentations. We believe that all of these papers and topics not only provide novel ideas, new results, work in progress and state-of-the-art techniques in this ?eld, but also stimulate the future research activities in the area of parallel and distributed computing with applications.