In reality, traditional process control system built upon centralized and hierarchical structures presents a weak response to change and is easy to shut down by single failure. Aiming at these problems, a new agent-based service-oriented integration architecture was proposed for chemical process automation system. Web services were dynamically orchestrated on the internet and agent behaviorswere built in them. Data analysis, model, optimization, control, fault diagnosis and so on were capsuled into differentweb services. Agentswere used for service compositions by negotiation. A prototype system of poly(ethylene terephthalate) process automation was used as the case study to demonstrate the validation of the integration. (C) 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.