Abstract: With the development of scrviccoriented computing, the users' tasks become more and more complicated.Thus,how to integrate all existing component services effectively to form a new valu}added services,as same as composite scrvice,which can content complex tasks has become a top research. Based on these service selection problems of valued-added services, this paper designs a discrete quantum particle swarm algorithm for enhancing trust, Comparing with traditional service selection algorithm, which is Qos-oriented for global optimization, this algorithm consider the issue of trust services which can solve the issue of trust in service workflow. At the same time, this algorithm disperses quantum particle swarm with the features of workflow. It redefines the computed methods of various locations and the auto-rcgulation of weight coefficient in quantum particle swarm algorithm according to the scenarios of service selcction. Compared with other similar research work, the time of service selection is reduced and a better fitness value can be got by this method. Simultaneously, the success rate of service selection is raised because of considering the issue of trust.

Key words: Composite service, Service selection, Quantum particle swarm, Discrete quantum particle swarm optimiza- tion,Trust valu}added